• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.735-747
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• 2018

Radon radiation exposures in home have been posed as a potential cancer hazard. This research aims to present the basic data of the indoor radon concentration level by examining the radon exhalation rates of wood species. Radon exhalation rates from five commonly used wood species in Korean wood building construction were measured with Continuous Radon Monitor (CRM), Model 1028 (Sun Nuclear Co., USA) using the Closed Chamber Method (CCM). The mass exhalation rate was observed to vary from $0.00089Bq{\cdot}kg^{-1}{\cdot}h^{-1}$ to $0.00181Bq{\cdot}kg^{-1}{\cdot}h^{-1}$, whereas the surface exhalation rate was observed to be $0.00677-0.01517Bq{\cdot}m^{-2}{\cdot}h^{-1}$. The radon exhalation rate of Quercus accutissima Carruth (white oak) which has the highest density showed the highest figure among the five wood species, on the other hand, the rest of four species showed similar results which were similar to the radon exhalation rates of wood in the U.S.A. and Canada. The average of the concentration measured by the CCM represented well up to the second half-life period (7.7 days). Because result of these small quantities seems to indicate that radon exhalation from the tested wood species has almost negligible impact, the main culprit of the high indoor radon concentration is clearly derived from the background of surrounding wood house. Therefore, as a safety precaution, infrastructures made of wood materials should be designed with the consideration of influx of radon and built accordingly. Furthermore, it is highly desirable that wood will be needed to use for furniture and interior finishing material in indoor environment.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.176-186
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• 1998

Pure Pt, Co and their alloy thin films with three different compositions (Pt66-Co34, Pt40-Co60 and Pt18-Co82) were deposited on Si(100) wafers and proposed as a set of certified reference materials (CRM) for the quantification and standardization of surface compositional analysis. The compositions of the binary alloy thin films were controlled by in-situ XPS analyses and the certified compositions of the films have been determined by ICP-AES and RBS analyses after thin film growth. Through comparison of the compositions determined by in-situ XPS with those by ICP, relatively accurate compositions could be obtained with a matrix effect correction. Standard deviations of XPS and AES round robin tests with the Pt-Co alloy thin films were large up to about 4%. On the other hand, the average compositions of the Pt-Co alloy thin films by two methods were in a good agreement within 1%. The formation of a Pt rich surface layer by ion beam sputtering indicates that the surface modification by preferential sputtering must be understood for a better compositional analysis.

• Analytical Science and Technology
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• v.18 no.1
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• pp.74-84
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• 2005

Understandings of adsorption characteristic of interface are very important in several advanced materials processes, related to NT and BT technology. Volumetric gas adsorption method, suitable for absolute measurements, is regarded as the standardized measurement technique for specific surface area. In order to verify the reliability of commercial equipments, certified reference materials (called CRM) of specific surface area are developed and evaluated its uncertainty factors by standard equipment which has traceability to SI units. Specific surface areas of developed materials are $10.72{\pm}0.46m^2g^{-1}$ for silicon nitride powders and $149.50{\pm}3.44m^2g^{-1}$ for alumina. These disseminations of CRMs would result in improved reliability chains in industrial processes, and lead eventually to contribution to productivity improvement, quality management, safety evaluation, and possibly to new material development.

• Analytical Science and Technology
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• v.31 no.3
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• pp.134-142
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• 2018

The uranium isotopic ratio in environmental samples around nuclear facilities is important because it reveals information regarding illegal activities or anthropogenic pollution. Determination of uranium isotopes, however, is a challenging task requiring much labor and time because of the complex separation procedures and lengthy process. In this study, a rapid determination method for uranium isotopes in environmental samples was developed using. The sample was completely decomposed using the alkali fusion method. The separation procedure using extraction chromatography (UTEVA) was simplified in a single step without any further removal process for Si and major matrix elements. The established method can be completed within 3 h from sample dissolution to ICP-MS measurement. Most matrix elements and uranium isotopes in the soil samples were well separated and purified. Five types of were used to assess the method's accuracy and precision for a rapid uranium analysis method. The analytical accuracy for all CRM samples ranged from 95.1 % to 97.8 %, and the relative standard deviation was below 3.9 %. From the analytical results, one may draw conclusions that the evaluated method for uranium isotopes using alkali-fusion, the extraction chromatography process, and ICP-MS measurements is fast and fairly reliable owing to its recovering efficiencies. Thus, it is expected that the evaluated method can contribute to the improvement of environmental monitoring ability.

• Archives of design research
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• v.15 no.4
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• pp.149-156
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• 2002

The success of a product is only possible on the basis of user preference for products and the user preference for products is greatly influenced by the design. Designers have to understand user preference and convert it into the combination of specified design attribute, and after that they should design products which have the image that they want to get. Then the product will be sure to be a hit. Therefore, on the point of view of design, it is necessary to find oui definitely the consumer preference frame : the relationship among design preference - design images - design attribute. This study will give you guidelines on which designers can select and design some more objective and reliable design factors, finding out the relation of cause and effect by which they can know what kind of product designs their consumers like and how the popular image which that products offer is composed of. Therefore, in this study, after we developed the consumer response framework which is proposed by Bloch(1995) : distinct relationship model among preference - design image adjective - design factors, we analyzed the relationship among preference-design image adjective - design factors through the empirical researches. And then we give the way of design.

• Journal of Intelligence and Information Systems
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• v.7 no.2
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• pp.35-49
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• 2001

Over the years, cluster analysis has become a popular tool for marketing and segmentation researchers. There are various methods for cluster analysis. Among them, K-means partitioning cluster analysis is the most popular segmentation method. However, because the cluster analysis is very sensitive to the initial configurations of the data set at hand, it becomes an important issue to select an appropriate starting configuration that is comparable with the clustering of the whole data so as to improve the reliability of the clustering results. Many programs for K-mean cluster analysis employ various methods to choose the initial seeds and compute the centroids of clusters. In this paper, we suggest a methodology to evaluate various clustering programs. Furthermore, to explore the usability of the methodology, we evaluate four clustering programs by using the methodology.

• Knowledge Management Research
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• v.17 no.2
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• pp.1-26
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• 2016

As entry barriers at the legal service market in Korea have been recently lifted, the legal service market has dramatically changed from a seller's market to a buyer's market. Externally, the Korean legal service market has been open to foreign law firms and internally, lawyers graduating from law schools have been increasing. In addition, as even the general public can easily access, through the official sites of government organizations, to the basic legal information such as laws and judicial precedents, the degree of information asymmetry has also decreased. These phenomena require the legal service industry to be a more client-oriented and more quality-oriented one. Having said that, legal service providers also need to continue to make strenuous efforts to measure and improve the service quality from the customers' perspective. Under these circumstances, this study introduced a certain type of model which may be of help of measuring and improving the quality of legal service of law firms, in particular, with a focus on those firms providing corporate legal service. This study used a Quality Function Deployment (QFD) in order to measure and thereby improve the quality of corporate legal service in the law firm industry. Above all, this study showed, by using SERVQUAL, each and every service attributes of quality measurement of the corporate legal service and also calculated the degree of importance of service quality at each process of providing corporate legal service. Next, this study introduced all supporting factors necessary for the provision of corporate legal service and calculated the degree of importance of each and every supporting factors in the service process. This study may be of help to provide the substantial and systematic approaches to the corporate legal service providers who would like to set up a certain methods of measuring and further improving the quality of corporate legal service from the customers' perspective.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.753-758
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• 2006

The recent drastic increase of imported foreign restaurants provided the importance of service quality and the customer satisfaction is considered as the most important factors for the business activity. In order to identify the important factors for the customer satisfaction of the family restaurant in Korea, we attempt to test the validity of host call service as a significant variable in the family restaurant using Fishbein behaviour model. Based on literature review, the empirical study was conducted using the questionnaires for customers of the family restaurant in Seoul. Descriptive statistics, t-test, F-test and regression analysis were made of the gathered questionnaires using SPSS programs. The results shows that four hypotheses established in this study were significant. Therefore, host call service in the family restaurant should be introduced to increase the customer satisfaction. In conclusion, it proved that host call service in the family were the important factors that could satisfy the customers and the family restaurants will have to make a great effort to develop the differentiated service so as to enhance their competitiveness.

• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.791-799
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• 2008

Ansim Flat DATA Plan is a DATA additional service product related to DATA call in a mobile telephone company A. Up to now, the company A is selling it by outbound TM after targeting customers which used data within specific price band. In this paper, we propose a targeting method applying score model combining response rate and retention rate by data mining. The suggested target model is to find customers more likely not only to respond to outbound TM but also to retain Ansim Flat DATA Plan. The proposed targeting method is expected to improve both from 23.7% to 38.8% in the response rate and from 53.2% to 61.4% in the retention rate.

• Journal of the Korean Data and Information Science Society
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• v.24 no.2
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• pp.245-255
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• 2013

The object of study is to propose a method for grouping R, F, and M in RFM model. Our model uses 6 levels using standard normal distribution. First level is upper 2.5% and second level next 13.5%, third level next 34%, fourth level next 34%, fifth level next 13.5%, sixth level next 2.5%. Values are symmetric and limits are clear. We compare proposed model with traditional 5 level model and 10 level model using NDSL data of KISTI. Proposed model divides most clearly the distribution of the RFM function for all cases of weights, because it uses the distribution of customers. Comparison studies of our model with grouping using cluster analysis and studies on weights of RFM model are needed.