• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1044-1049
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• 2001

Classical deconvolution methods for source identification following linear filtering can only be used if the transfer function of the system is known. For many practical situations, however, this information is not accessible and/or is time varying. The problem addressed here is that of reconstruction of the original input from only the measured signal. This is known as 'blind deconvolution'. By using Higher Order Statistics (HOS), the restoration of the input signal is established through the maximisation of higher order moments (cumulants) with respect to the characteristics of the signals concerned. This restoration is achieved by constructing an inverse filter considering the choice of the initial inverse filter type. As a practical application, an experimental verification is carried out for the restoration of our impacting signal arising in the response of a cantilever beam with an end stop when randomly excited.

• The Research Journal of the Costume Culture
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• v.8 no.3
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• pp.339-348
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• 2000

The purpose of this research was to offer basic data for study of men's suits by investigating the buying conditions of men's suits. For data collection, a questionnaire was composed of a purchasing price, a purchasing place, the source of the information, the reason of the suit buying, a standard for choice, recognition of the ready-made suit's size and a number of suits they buy etc. The subjects of this research were male who aged 20∼59 and resided in Seoul and the capital region. The results of the research were summarized as the following : 1. Most of the men purchased a ready-made suit rather than a custom suit and a easy-order suit because of the convenience for buying. But the elder was tend to purchase a custom suit than the younger. And the reason of custom suit or easy-order suit buying was size for fitness. 2. It was usually done in a department store and an agency as a purchasing place. The men who resided in Seoul used a department store more than ones who resided in the capital region. Most of the men used bargain sale. The source of the information of suits came principally himself and a wife. Most of the men purchased the suits with their wives of themselves. The elder depended upon their wives for buying suit than the younger. The standards for buying the ready-made suit were color, style and price. The number of suit they buy in a year was 0.9 suits for S/F, 0.7 suits for winter, 0.4 suits for summer and 0.2 suits for combination. The main purchasing price was 150,000∼250,000 won. 3. Most of the consummer was to be satisfied a sense of wearing, color, design etc, but they ware not to be satisfied price, A/S, size etc for ready-made suits. And they usually didn't know the size of ready-made suits.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.193-199
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• 2017

This study applied the scenario of the film "Warcraft: The Beginning, 2016" based on the world view and nonlinear story of online games to the basic requirements of a good story of five items. Based on this, it was found that the storyline of the film "Warcraft: The Beginning, 2016" was faithful to the game series with the same title, but weak for a film. This film did not satisfy any of the five requirements of a good scenario used for Hollywood production. Even before this film, many hit games were made into films, but box office hits are hard to find among them. As the game World of Warcraft was very famous worldwide, when it was made into a film, the film was expected to be a box office hit. However, it failed miserably at the box office. This is a result of failing to recognize that the characteristics of games that an individual leads the story are different from those of films that no interaction or choice can be made. It is necessary to understand that although games and films are the same in that they have narrative structures and visual stimulation graphics, they are totally different in the way they immerse people.

• Korean Journal of Community Nutrition
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• v.12 no.6
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• pp.815-825
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• 2007

The study was designed to investigate food waste management practices and to identify factors affecting food waste generation at school food services. A total of 202 dietitians employed at elementary schools participated in the survey. The mean food waste weight per school was 77.54 kg, forty percent of the schools generated food waste of $50{\sim}100kg$ every day and 53% generated plate waste less than 50 kg. Three quarters of the dietitians perceived plate waste as a major component of the food waste and vegetable dishes were a major source of the plate waste. Half of the dietitians used a food waste pick-up service for waste disposal, which was the most preferred waste disposal method. Approximately 90% of the dietitians conducted education on plate waste reduction for students but their perceptions on the effectiveness of the education was inconsistent. The contents were environmental issues (70.3%) and unbalanced food choice (56.7%). According to factor analysis based on performance score, solid waste management practices were grouped into 'information collecting and education', 'supervision of production process', 'cooperation with related groups', and 'control over production planning'. Practices appertaining to 'cooperation with related groups', 'information collecting and education' factor need to be improved. Dietitians should pay attention to 'recycle and reuse of left over' practice. Waste generation differed significantly by dietitians' ages and working experience. In order to reduce plate waste, more effective education materials and methods need to be developed and support from principals, teachers, and parents is necessary.

• Journal of the Korean Society of Costume
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• v.49
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• pp.125-136
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• 1999

The present study was conducted to analyze(1) if there are any differences in jean's brand royalty according to the age·sex·educational background and income of consumers (2) the criteria for store choice by jean's brand royalty of consumers (3) the use of information souces by jean's brand royalty of consumers. The research method employed was normative-descriptive survey and questionnaires were main instrument to gather research materials. The survey was implemented from July 1st 1998 to the schools and two colleges and those who work at a comuter-related company and at a trade company. The data gathered was analyzed by mean standard deviation t-test ANOVA and Duncan -multiple range test. The results are summarized as follows: (1) 58.6% of the respondents were categorized as the brand loyalty group that was bigger than the non-brand loyalty group (41.4%) People in their late 2-'s were inclined to have the highest brand loyalty for jeans People in university and above had relatively higher brand royalty than to people with a high school or lower (2) Brand royalty group paid more attention on the quality on the quality of the fabric use; the trands of the products: brand name of the product: the distance of the store location : and the comfortable atmosphere of the store. Pleasant and kind services of the salesperson was considered as more important factor for store selection by the non-brand royalty group than by brand royalty group. (3) Almost all the information sources were used more often by brand royalty group than non-brand royalty group. For both groups their own experiences is most important information sources. The results shows that consumers have high brand loyalty for jeans product and also have many differences not only in the usage of information sources but also in the store selection criteria accorrding to the level of jeans brand loyalty . Therefore those industries carrying jeans should these points on their marketing strategies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.2972-2991
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• 2016

WLAN is the best choice in the place where complex network is hard to set up. Intelligent terminals are more and more assembled in some areas now. However, according to IEEE 802.11n/802.11ac, the access-point (AP) can only serve one user at a single frequency channel. The spectrum efficiency urgently needs to be improved. In theory, AP with multi-antenna can serve multiple users if these users do not interfere with each other. In this paper, we propose a user clustering scheme that could achieve multi-user selection through the mutual cooperation among users. We focus on two points, one is to achieve multi-user communication with multiple antennas technique at a single frequency channel, and the other one is to use a way of distributed users' collaboration to determine the multi-user selection for user clustering. Firstly, we use the CSMA/CA protocol to select the first user, and then we set this user as a source node using users' cooperation to search other proper users. With the help of the users' broadcast cooperation, we can search and select other appropriate user (while the number of access users is limited by the number of antennas in AP) to access AP with the first user simultaneously. In the network node searching, we propose a maximum degree energy routing searching algorithm, which uses the shortest time and traverses as many users as possible. We carried out the necessary analysis and simulation to prove the feasibility of the scheme. We hope this work may provide a new idea for the solution of the multiple access problem.

• Journal of Distribution Science
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• v.14 no.4
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• pp.117-125
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• 2016

Purpose - As consumers' needs for purchasing fresh and safe food have been bigger in Korea, their interest in local food is also growing recently. So, the number of local food stores has been increased from 3 in 2012 to 103 in 2015. Local food stores should operate a business responding consumers' needs in order that local food stores are not to be a one-time fad. Therefore, the purpose of this study is to analyze the characteristics of consumers who use a local food store and provide helpful implications to design a strategy for sustainable growth of local food store. Research design, data, and methodology - In this study, Probit model was used for empirical analysis in order to examine the effect of purchase choice attributes of agricultural products, consumer's satisfaction, and their demographic factors upon the intention to use a local food store. After estimating coefficients of the probit model, marginal effects were calculated as a standard normal, and cumulative distribution is differentiated with respect to explanatory variables. To collect the data, questionnaire survey was carried out with the consumers using the local food store (Youngjin Nonghyup near to Jeonju city located in Jeollabuk-do). Result - The data analysis found that the more consumers are satisfied with local food store, the higher intention they have to use the local food store. In addition, it was known that the factors related to quality of agricultural products and shopping convenience among the purchase choice attributes have a considerable impact on the purchase intention of a local food store. In demographic factors, income was turned out to be an important factor affecting purchase intention of local food. Such a result supports the hypothesis that high income consumers are likely to purchase local food, which is based on the inference that consumers who have a high income tend to pursue wellbeing life. Futhermore, information delivery, through a reputable media source among general factors, was known to play an important role in forming an intention to purchase local food. According to the analysis of marginal effects, probability of purchase intention of a local food store is increased by 11.4%, if a monthly average income of a household is above 4.5 million Won(Korean currency). If purchasing satisfaction with local food stores is high, the probability of purchase intention would be increased by 24.1%. Likewise, such a probability goes up by 8.7%, 5.8%, respectively as an increasing one unit of quality of agricultural products and shopping convenience of local food stores, respectively. Conclusion - For attaining sustainable growth in a local food store, it is considered necessarily to establish a proper store operation system to meet consumers' needs, especially for quality and shopping convenience of local food. Moreover, as it was found that appropriate communication through media source has a positive effect on the intention to use local food store, PR activity seems to be necessary to expand the consumers' demands for local foods.

• KSBB Journal
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• v.23 no.4
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• pp.335-339
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• 2008

Biodiesel is an alternative and renewable energy source, which is hoped to reduce global dependence on petroleum and environmental problem. Biodiesel produced from a variety of oil sources such as vegetable oil, animal fat and waste oils, and has properties similar to those associated with petro-diesel, including cetane number, volumetric heating value, flash point, viscosity and so on. In this study, we investigate the effect of quality of raw materials on alkali-catalyzed transesterification for producing of biodiesel. The increase of content of free fatty acid and water in oil were caused the sharp decrease of conversion yield. Also, the low purity of methanol in reactant was inhibited the reaction rate. In the case of addition of sodium sulfate as absorbent to prepare catalyst solution, the content of fatty acid methyl ester in product was increased more about 1.6% than that of control. However, the addition of zeolite, sodium chloride and sodium sulfate as absorbent in reactant to remove water generated from reaction did not show any enhancement in the reaction yield. This result may provide useful information with regard to the choice and preparation of raw materials for more economic and efficient biodiesel production.

• International Journal of Reliability and Applications
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• v.13 no.1
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• pp.19-35
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• 2012

This paper presents an optimum design of step-stress partially accelerated life test (PALT) plan which allows the test condition to be changed from use to accelerated condition on the occurrence of fixed number of failures. Various life distribution models such as exponential, Weibull, log-logistic, Burr type-Xii, etc have been used in the literature to analyze the PALT data. The need of different life distribution models is necessitated as in the presence of a limited source of data as typically occurs with modern devices having high reliability, the use of correct life distribution model helps in preventing the choice of unnecessary and expensive planned replacements. Truncated distributions arise when sample selection is not possible in some sub-region of sample space. In this paper it is assumed that the lifetimes of the items follow Truncated Logistic distribution truncated at point zero since time to failure of an item cannot be negative. Optimum step-stress PALT plan that finds the optimal proportion of units failed at normal use condition is determined by using the D-optimality criterion. The method developed has been explained using a numerical example. Sensitivity analysis and comparative study have also been carried out.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.26-32
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• 2020

Background: Pollen is an important source of protein and lipids for many animals including honey bees. In order to understand the foraging behaviour of honey bee colonies and preference among the available floral resources, pollen collections from three experimental healthy colonies of honey bees were analysed in the month of June. Results: The amount of pollen collections were related to the colony's need which was indicated by the number of larval and adult bees present in the hive. Interesting was the sequence of pollen collection from different floral sources. All honey bee colonies collected pollens from Trifolium repens first, then Erigeron annus and the third choice was Coreopsis drummondii and Oenothera biennis flowers. Total protein content of Trifolium pollen was the highest (20.0 g/100 g DM), and the others were in the range of 8.9-11.4 g/100 g DM. Conclusion: The results indicated that the first criteria for honey bee foraging preference of pollens would be the nutritional contents of protein and the resource availability of the lesser nutritious floral sources. This information can help pollinator protection programmes of habitat manipulation using flowering plants for nectar and pollen sources.