• Journal of Digital Convergence
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• v.19 no.10
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• pp.253-263
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• 2021

Machine learning is the process of constructing a cost function using learning data used for learning and an artificial neural network to predict the data, and finding parameters that minimize the cost function. Parameters are changed by using the gradient-based method of the cost function. The more complex the digital signal and the more complex the problem to be learned, the more complex and deeper the structure of the artificial neural network. Such a complex and deep neural network structure can cause over-fitting problems. In order to avoid over-fitting, a weight decay regularization method of parameters is used. We additionally use the value of the cost function in this method. In this way, the accuracy of machine learning is improved, and the superiority is confirmed through numerical experiments. These results derive accurate values for a wide range of artificial intelligence data through machine learning.

• Textile Coloration and Finishing
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• v.21 no.1
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• pp.59-66
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• 2009

The seven kinds of polyester fabrics having different fabric characteristics were investigated in terms of their dyeing levelness under various liquor ratios. The levelness was evaluated statistically from color strength obtained at different sections of each piece of dyed fabrics. The color strength data were analyzed using a exponential decay function of 3 parameters, $y=y_0+ae^{-bx}$. The b value of the function was used as a index of sensitiveness of dependence on liquor ratio of levelness. The index, b value, showed a linear proportional relationship to thickness of fabrics. Average unlevelness of dyeings exhibited a inverse proportional relationship to both weight and thickness of fabrics.

• English Language & Literature Teaching
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• v.13 no.2
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• pp.47-61
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• 2007

The purpose of this paper is to survey the major elements that have changed English from a synthetic language to an analytic one. Therefore, this paper has looked at the differences between synthetic languages and analytic ones. In synthetic languages, the relation of words in a sentence is synthetically determined by means of inflections, while in analytic languages, the functions of words in a sentence are analytically determined by means of word order and function words. Thus, Old English with full inflectional systems shows the synthetic nature. However, in the course of time, Old English inflections came to be lost by phonetic changes and operation, which made English dependent on word order and function words to signal the relation of words in a sentence. The major phonetic changes that have shifted English are the change of final /m/ to /n/, the leveling of unstressed vowels, the loss of final /n/, and the decay of schwa in final syllables. These changes led to reduction of inflections of English as well as the loss of grammatical gender. The operation of analogy, the tendency of language to follow certain patterns and to adapt a less common form to a more familiar one, has also played an important role in changing English.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.270-276
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• 2020

In this paper, we analyze the buyer's joint pricing and lot-sizing model in a two-stage supply chain consisting of the supplier, the buyer and the customer. It is assumed that the supplier will permit a certain fixed period for settling the amount the buyer owes to him for the items supplied in order to stimulate the demand for the product. Generally, credit transactions would have a positive effect to the buyer. The availability of credit transactions from the supplier effectively reduces the cost of holding stocks for the buyer and therefore, the buyer has a lot of price options to choose his sales price for a customer in anticipation of increased the customer's demand and, as a result, it will appear to increase the buyer's inventory levels. On the other hand, in the case of decaying products in which their utility decay over time, the decaying rate with time may be expected to reduce inventory levels. In this regard, we need to analyze how much the length of credit period and the decaying rate affect the buyer's pricing and lot-sizing policy. For the analysis, we consider the situation where the customer's demand is represented as a linearly decreasing function of the buyer's sales price. From this perspective, we formulate the buyer's annual net profit and analyze the effect of the length of credit period and decaying rate of the product on the buyer's inventory policy numerically.

• Journal of radiological science and technology
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• v.33 no.4
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• pp.363-367
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• 2010

In this paper we proposed an easy method to calculate the thickness of primary protective barrier for radiographic equipment. The concrete was selected for the shielding material. The area of protective barrier was divided into a controlled area and a noncontrolled area. For the computation of thickness, the data in NCRP Report 49 and 51 was used. For radiographic equipments whose maximum tubevoltages are 100 and 150 kVp, the thicknesses of concrete were calculated as a function of distance. From the calculated data, four analytical models were acquired by fitting an exponential decay function. From the equations acquired by this study, the thickness of primary protective barrier can be calculated approximately.

• Journal of Korea Planning Association
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• v.54 no.2
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• pp.76-83
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• 2019

This study aims to empirically identify the effect of spatial accessibility, based on travel, on housing prices in the Korean capital region. More specifically, it has two research purposes: First, investigating the effect of comprehensive spatial accessibility, based on road network and actual trips from origin to destination, on average apartment price (Korean Won per square meter) at the level of Eup, Myeon and Dong; Second, identifying better accessibility index between Hansen's and Kalogirou and Foley's ones. The former represents a road-based travel time decay function with destination trips, while the latter is a function with origin trips as well as destination ones. The study employs spatial economic models considering spatial auto-correlative relationship as an appropriate methodology with such control independent indicators as population density, road density, educational environment and distances from CBDs. Analysis results demonstrate that spatial accessibility, based on road network and actual trips from origin to destination, has a statistically significant impacts on housing price in the region. Our empirical evidence proves that the Hansen index is more appropriate than the other in estimating housing price impacts.

• Journal of Intelligence and Information Systems
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• v.14 no.2
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• pp.207-222
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• 2008

This research suggests the method of how to build agricultural and stockbreeding products recommender systems based on RFID technology for monitoring crop and livestock production, tracing production history as an application strategy. In the past the studies on enterprise applications have been barely implemented owing to the rack of business model and limitation of technical development. Currently however there have been enormous technological progress of RFID and agricultural and stockbreeding products retailing sites are increased. Therefore this paper suggests PDCF-ASP(Profile Decay based Collaborative Fltering for Agricultural and Stockbreeding Products) which is designed to reduce customers… search efforts in finding safety and fresh products on the internet shopping mall. For this, product decay function is defined to make sure whether the products are safety or not and to adopt a change in customer preferences. And for the implementation of PDCF-ASP, the system structure including functional agents is schematized.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.123-128
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• 2004

Both photoluminescence and the long-phosphorescent properties for $SrAl_2O_4$ : Eu$^{+2}$, $Dy^{+3}$ phosphor powder synthesized by the solid phase reaction were investigated as a function of $B_2O_3$ composition (0-10 wt%). The highest emission wavelength (520nm) of photoluminescence spectra was not affected by $B_2O_3$concentration. The highest emission intensity was obtained by the concentration of 3 wt% $B_2O_3$.After the removal of the Xenon lamp excitation (360nm), also, the excellent long-phosphorescent property of the phosphors was obtained by the concentration of 3 wt% $B_2O_3$ although the decay times for all phosphors decreased exponentially.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.137-149
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• 1998

It is likely that the spatial structure of the intraurban accessibility as well as the accessibility value of each of the nodes in the subway network is affected by the addition of new linkages. The changes in the accessibility at individual nodes also affect the accessibility in the surrounding areas at some distances away from the nodes. Graph-theoretic algorithms have been developed as a proper measurement scheme for the nodal accessibility in tracked transport networks such as subway networks. However, the graph-theoretic measurements have limitations to estimate the spatial diffusion effect on the surrounding areas. This study proposes a new model for the spatial diffusion effect estimation of nodal accessibility increment in the subway network toward the surrounding areas. Since the distance decay trend of subway station use reflect the spatial diffusion effect of the accessibility of subway station toward the surrounding area. The model is deduced from the subway station use density function which is formulated by the questionnaire survey data.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.217-223
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• 2013

This paper presents the wet damping estimation of the segmented hull model using the random decrement technique together with the continuous wavelet transform. The tested 16 sea states are grouped together based on the speed of the ship in order to figure out the possible influence of the ship speed on the damping ratio. The measured time histories of vertical bending moment for each tested sea state were processed with random decrement technique to derive the free decay signal, from which the damping ratios are estimated. Also, the autocorrelation functions of the filtered signal were calculated and comparison was made with the free decay signal obtained from the random decrement technique. Then the wet damping ratios for each sea state group, as well as precise wet natural frequencies, are estimated by using continuous wavelet transform. It turned out that the wet natural frequencies derived from the measured signal did not show any significant discrepancy compared with those obtained by wet hammering test, whereas the damping ratio did. It was considered that the discrepancy of the damping ratio between in calm and moving water may be attributed to the viscous effects caused by dramatically different flow pattern and relative velocity between the vibrating structure and surrounding fluid particles.