• Spatial Information Research
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• v.6 no.2
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• pp.133-152
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• 1998

This article considers the experimental foundations of geographical phenomena for the distribution of lodging houses and the development of lodging Information Systems in Shin-Chon Area. This system allows the rural students to find their lodging houses conveniently. We examine the geographical reality of lodging houses in Shin-chon area and explores the lodging information system, reflecting how students select the lodging houses. Criteria for selection of lodging houses are travel time to school, interior facilities, rent fee, members, owners of lodging houses, which are collected by field swvey. The lodging information system is built in integration of Visual Basic with spatial data which are created in Mapinfo and Arcview through MapObject, component GIS software. This system provide query tools to efficiently investigate data as well as interactive map display. Also it displays the characteristics of a selected lodging houses using the identify tool on the map.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.39-54
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• 2013

Recent explosive increase of electronic commerce provides many advantageous purchase opportunities to customers. In this situation, customers who do not have enough knowledge about their purchases, may accept product recommendations. Product recommender systems automatically reflect user's preference and provide recommendation list to the users. Thus, product recommender system in online shopping store has been known as one of the most popular tools for one-to-one marketing. However, recommender systems which do not properly reflect user's preference cause user's disappointment and waste of time. In this study, we propose a novel recommender system which uses data mining and multi-model ensemble techniques to enhance the recommendation performance through reflecting the precise user's preference. The research data is collected from the real-world online shopping store, which deals products from famous art galleries and museums in Korea. The data initially contain 5759 transaction data, but finally remain 3167 transaction data after deletion of null data. In this study, we transform the categorical variables into dummy variables and exclude outlier data. The proposed model consists of two steps. The first step predicts customers who have high likelihood to purchase products in the online shopping store. In this step, we first use logistic regression, decision trees, and artificial neural networks to predict customers who have high likelihood to purchase products in each product group. We perform above data mining techniques using SAS E-Miner software. In this study, we partition datasets into two sets as modeling and validation sets for the logistic regression and decision trees. We also partition datasets into three sets as training, test, and validation sets for the artificial neural network model. The validation dataset is equal for the all experiments. Then we composite the results of each predictor using the multi-model ensemble techniques such as bagging and bumping. Bagging is the abbreviation of "Bootstrap Aggregation" and it composite outputs from several machine learning techniques for raising the performance and stability of prediction or classification. This technique is special form of the averaging method. Bumping is the abbreviation of "Bootstrap Umbrella of Model Parameter," and it only considers the model which has the lowest error value. The results show that bumping outperforms bagging and the other predictors except for "Poster" product group. For the "Poster" product group, artificial neural network model performs better than the other models. In the second step, we use the market basket analysis to extract association rules for co-purchased products. We can extract thirty one association rules according to values of Lift, Support, and Confidence measure. We set the minimum transaction frequency to support associations as 5%, maximum number of items in an association as 4, and minimum confidence for rule generation as 10%. This study also excludes the extracted association rules below 1 of lift value. We finally get fifteen association rules by excluding duplicate rules. Among the fifteen association rules, eleven rules contain association between products in "Office Supplies" product group, one rules include the association between "Office Supplies" and "Fashion" product groups, and other three rules contain association between "Office Supplies" and "Home Decoration" product groups. Finally, the proposed product recommender systems provides list of recommendations to the proper customers. We test the usability of the proposed system by using prototype and real-world transaction and profile data. For this end, we construct the prototype system by using the ASP, Java Script and Microsoft Access. In addition, we survey about user satisfaction for the recommended product list from the proposed system and the randomly selected product lists. The participants for the survey are 173 persons who use MSN Messenger, Daum Caf$\acute{e}$, and P2P services. We evaluate the user satisfaction using five-scale Likert measure. This study also performs "Paired Sample T-test" for the results of the survey. The results show that the proposed model outperforms the random selection model with 1% statistical significance level. It means that the users satisfied the recommended product list significantly. The results also show that the proposed system may be useful in real-world online shopping store.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.283-293
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• 2002

Purpose : A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 30 dose distributions. Materials and Methods : Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dosevolume histogram. Results : The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a $200\times200\;(mm^2)$ plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were $4.5\~9.0\%$ smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed $1\~5\%$ discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. Conclusion : This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

• 한국호스피스완화의료학회:학술대회논문집
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• 2004.07a
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• pp.100-102
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• 2004

Under the current medical system, a terminal patient and his/her family who are neglected inevitably face various aspects of crises including not only physical, but also psychological, social, economic, spiritual and legal problems. Nurses often look after many terminal patents with these types of complicated problems. Therefore, educating the nurses who will take care of such patents would greatly reduce stress so the patents end could their lives in peace and without losing their dignity. This research is a quasi experimental study of nonequivalent control group. A pretest-posttest design where a basic education program is developed for nurses, who frequently treat terminal patents, to understand the importance of the role of hospice and to apply their understandings to treat terminal lancer patents. A sample of the nurses were taken from those who were working in general wards at two general hospitals in Seoul during October, 2003${\sim}$December 2003. The study was composed of 46 experimental group and 43 control group. A basic hospice education program was developed by taking emphasized and overlapping parts from advanced practice hospice nurses education course, short-term education course, an extensive literature survey and by consulting three professionals as well. With the group of 5 professors with vast experiences in oncolgy, 5 nursing administrator, 3 nursing practitioner, the tentative first version of the program was developed and reviewed. Afterwards, by utilizing person to person interviews with 2 head nurses experienced with terminal patients, 1 nurse in charge of hospice, 1 nurse on the contents of the program, and a person to person rating on the educating medium by a nurse were performed. The final version of a basic education program was developed after the second revision. The hospice basic education program consists of introduction to hospice, hospice and commucation, management of pain for terminal cancer patients, physical management for terminal cancer patients, socio-psycological caring of terminal cancer patients and management of death and separation. Total education time was four hours organized into 50 minutes of instruction and 10 minutes of break. $Powerpoint^{(R)}$ software was used as the education medium. As research tools, "Knowledge on Hospice" was developed by the author after receiving a review from one expert. "Attitude of Hospice Nursing" was revised Kim(2001)'s attitude measuring tool which was based on Wang(1998), Kwon(1989), Park and Sung(1991)'s tool. "Liability on nursing terminal patients" was used as developed by Zarits(1980) and Mongomory(1985) translated by Lee(1985). For collecting data, preliminary investigation prior to 1 week of the hospice basic education program and post-investigations after 1 week and 4 weeks of the education were carried out for the nurses at a general ward who understood and agreed on the purpose of the program. Collected data were analyzed throughout t-test, $x^2-test$, Manova test and Bonferroni correction in $SAS^{(R)}$ program. The summary of the investigation is as follows: Hypothesis 1: "Educated experimental group would possess more knowledge on hospice compared to the un-educated control group" was supported after 1 (F=12.14, p=.00) and 4 (F=5.3, p=.02) weeks of education. Hypothesis 2: "Educated experimental group would take a positive attitude toward hospice nursing compared to the un-educated control group" was supported after 1(F=3.92, p=.05) and 4(F=5.05, p=.02) weeks of education. Hypothesis 3: "Educated experimental poop would feel less liability compared to the un-educated control group in nursing terminal cancer patients' was rejected. In this study, it was found that knowledge on hospice was significantly important. By applying hospice basic education programs to nurses, the education program helped nurses to take a positive attitude toward terminal patients. It was, however, seen that the education program had no effect on alleviating liability in nursing terminal patients. Therefore, it is expected that this educational program would help hospices and nurses at general wards to understand the concept and the role of hospice so that terminal patents, now neglected under current medical system, would be able to end their lives in peace.