• Asia pacific journal of information systems
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• v.20 no.1
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• pp.81-99
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• 2010

Lately, in consumers' markets the number of new items is rapidly increasing at an overwhelming rate while consumers have limited access to information about those new products in making a sensible, well-informed purchase. Therefore, item providers and customers need a system which recommends right items to right customers. Also, whenever new items are released, for instance, the recommender system specializing in new items can help item providers locate and identify potential customers. Currently, new items are being added to an existing system without being specially noted to consumers, making it difficult for consumers to identify and evaluate new products introduced in the markets. Most of previous approaches for recommender systems have to rely on the usage history of customers. For new items, this content-based (CB) approach is simply not available for the system to recommend those new items to potential consumers. Although collaborative filtering (CF) approach is not directly applicable to solve the new item problem, it would be a good idea to use the basic principle of CF which identifies similar customers, i,e. neighbors, and recommend items to those customers who have liked the similar items in the past. This research aims to suggest a hybrid recommendation procedure based on the preference boundary of target customer. We suggest the hybrid recommendation procedure using the preference boundary in the feature space for recommending new items only. The basic principle is that if a new item belongs within the preference boundary of a target customer, then it is evaluated to be preferred by the customer. Customers' preferences and characteristics of items including new items are represented in a feature space, and the scope or boundary of the target customer's preference is extended to those of neighbors'. The new item recommendation procedure consists of three steps. The first step is analyzing the profile of items, which are represented as k-dimensional feature values. The second step is to determine the representative point of the target customer's preference boundary, the centroid, based on a personal information set. To determine the centroid of preference boundary of a target customer, three algorithms are developed in this research: one is using the centroid of a target customer only (TC), the other is using centroid of a (dummy) big target customer that is composed of a target customer and his/her neighbors (BC), and another is using centroids of a target customer and his/her neighbors (NC). The third step is to determine the range of the preference boundary, the radius. The suggested algorithm Is using the average distance (AD) between the centroid and all purchased items. We test whether the CF-based approach to determine the centroid of the preference boundary improves the recommendation quality or not. For this purpose, we develop two hybrid algorithms, BC and NC, which use neighbors when deciding centroid of the preference boundary. To test the validity of hybrid algorithms, BC and NC, we developed CB-algorithm, TC, which uses target customers only. We measured effectiveness scores of suggested algorithms and compared them through a series of experiments with a set of real mobile image transaction data. We spilt the period between 1st June 2004 and 31st July and the period between 1st August and 31st August 2004 as a training set and a test set, respectively. The training set Is used to make the preference boundary, and the test set is used to evaluate the performance of the suggested hybrid recommendation procedure. The main aim of this research Is to compare the hybrid recommendation algorithm with the CB algorithm. To evaluate the performance of each algorithm, we compare the purchased new item list in test period with the recommended item list which is recommended by suggested algorithms. So we employ the evaluation metric to hit the ratio for evaluating our algorithms. The hit ratio is defined as the ratio of the hit set size to the recommended set size. The hit set size means the number of success of recommendations in our experiment, and the test set size means the number of purchased items during the test period. Experimental test result shows the hit ratio of BC and NC is bigger than that of TC. This means using neighbors Is more effective to recommend new items. That is hybrid algorithm using CF is more effective when recommending to consumers new items than the algorithm using only CB. The reason of the smaller hit ratio of BC than that of NC is that BC is defined as a dummy or virtual customer who purchased all items of target customers' and neighbors'. That is centroid of BC often shifts from that of TC, so it tends to reflect skewed characters of target customer. So the recommendation algorithm using NC shows the best hit ratio, because NC has sufficient information about target customers and their neighbors without damaging the information about the target customers.

• Journal of The Korean Association For Science Education
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• v.37 no.3
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• pp.493-505
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• 2017

The purpose of this study is to investigate the trends of character-related research in science education by analyzing science education research literatures in South Korea. To this end, literatures on character were extracted from the KCI-listed journals and theses from 1990 to December 2016, and analyzed according to the criteria such as terms relating to character, year of publication, research design and method, and research content. A total of 54 KCI-listed papers and 67 theses were extracted. As a result, 46%, 49%, and 5% of the researches include the terms like character, ethic, and moral in their titles. According to the year of publication, it was found that the number of research papers related to character increased rapidly by more than two times in 2012 as compared to the past years. According to research objects, researches about gifted students were the most common, and when considering the ratio of gifted students to general students, many studies related to character concentrated on gifted students. Starting 2009, research papers on qualitative and hybrid research design begin to advance as compared the number of papers in quantitative research design. With regards to research methods used, seven methods were classified; five of them ranged from 16% to 19% while interpretive research method was 12% and test tool validity study was the lowest at 2%. By extracting 30 representative keywords so as to analyze the contents of character-related researches, we found various implications to character in relation to nature and researches about SSI, etc. As time passed by, the contents of character-related research in science education became more diversified and the number of researches increased. New research contents appeared due to the needs of the times.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.7-18
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• 2002

Generally, natural soils are affected by one-dimensional consolidation so that the behavior characteristic could be somewhat different from the isotropic consolidation specimen. But, due to experimental difficulties and the lack of equipment, the isotropic triaxial tests are mainly performed in most lab. tests. So it seems to be very effective if it is possible to predict pore water pressure and undrained shear strength in the $K_o$ state as the results of isotropic triaxial consolidation test. In this study, isotropic triaxial consolidation test and $K_o$ triaxial consolidation test were performed and we obtained parameters related to pore water pressure ratio using the Hyperbolic model. And then we predicted the behavior of pore water pressure that occurred in the $K_o$ state from the results obtained in the isotropic triaxial cosolidation test through the equation suggested by Lo(1969). It is possible to seize the validity of Lo(1969) equation. Also, considering undrained shear strength obtained from consolidation method in relation with water content, we find that consolidation method have an effect on undrained shear strength. Finally, using the Wroth(1984) equation that is based on the theory of critical state, undrained shear strength in the $K_o$ state was predicted from that of the isotropic triaxial consolidation test. The usefulness of the equation was verified by comparing the predicted value with experimental results.

• Therapeutic Science for Rehabilitation
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• v.10 no.3
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• pp.83-96
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• 2021

Objective : This study aimed to determine Korea-type family function factors that affect individual growth and social activities, and examine check the appropriate contents and domestic culture components based on the McMaster model, a family function evaluation tool, through the Delphi technique. Methods : The Delphi technique was applied to 12 expert panels in fields related to family function. The period lasted 9 weeks, from May to June 2020. The Delphi survey was conducted twice. In the first survey, the domestic culture and appropriate contents of the McMaster model were selected and localized, and expert' opinions about the components were collected using closed and open-ended questions. In the second survey, the fitness and importance of the components were investigated. Results : As a result of the first Delphi investigation, 18 items were deleted from the 53 items presented. After adding 11 items and excluding any overlapping items, a total of 40 items were selected. Subsequently, sentences that were difficult to understand were revised to familiar vocabulary. A second survey was constructed, with an example sentence. In the second Delphi investigation, 33 items were selected. The average content validity ratio for the final selected component was 0.76, and the stability was 0.28. Conclusion : Family function and the factors influencing domestic family function identified though this study can be used to conduct family function evaluations and interventions in clinical sites or relevant research studies.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.557-564
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• 2023

In this study, 3D printing technology was used to compensate for the shortcomings of the use of lead, which has proven to have excellent shielding performance, and to control unnecessary human exposure. 3D printers can implement three-dimensional shapes and can immediately apply individual ideas, which has great advantages in maintaining technology supplementation while reducing the cost and duration of prototyping. Among the various special 3D printers, the FDM method was adopted, and the filament used for output was manufactured using a research extruder by mixing two materials, PLA (Poly-Lactic-Acid) and tungsten. The purpose was to verify the validity through dose evaluation and to provide basic information on the production of chapezones of various materials. The mixed filament was implemented as a morphological shield. Filaments made of a research extruder by mixing PLA and tungsten were divided into 10 %, 20 %, 30 %, 40 %, and 50 % according to the tungsten content ratio. Through the process of 3D Modeling, STL File storage, G-code generation, and output, 10 cm × 10 cm × 0.5 cm was manufactured, respectively, and dose and shielding ability were evaluated under the conditions of tube voltages of 60 kVp, 80 kVp, 100 kVp, 120 kVp, and tube currents of 20 mAs and 40 mAs.

• Journal of Nutrition and Health
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• v.57 no.1
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• pp.136-152
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• 2024

Purpose: A comprehensive evaluation item was developed to assess adolescent dietary habits and nutritional practices, considering food intake, eating behaviors, and food culture, such as social support and food environment. Methods: The 59 candidate items of the evaluation checklist were obtained based on the results of the eighth Korea National Health and Nutrition Examination Survey data, Korea Dietary Reference Intakes, dietary guidelines for adolescents, Youth Risk Behavior Survey data, national nutrition policies and dietary guidelines, and literature reviews. Four hundred and three middle and high school students residing in metropolitan areas participated in a survey using the 58-item checklist, which was selected through expert evaluation and content validity ratio analysis. The construct validity of the assessment tool for the quality of adolescent diets was assessed by exploratory factor analyses to determine if the checklist items were organized properly and whether the responses to each item were distributed adequately. Results: The Bartlett sphericity test was significant for each area (p <0.001), and the eigen values were greater than one. The Kaiser-Meyer-Olkin and cumulative proportions by areas were food intake (0.765 and 56.8%, respectively), eating behaviors (0.544 and 64.8%, respectively), and food environment (0.699 and 62.4%, respectively). Twenty-two checklists were determined for the final evaluation items for the adolescents' dietary habits and nutritional practices and were categorized into three distinct factors: food intake (10 items), eating behaviors (4 items), and food environment (8 items). Conclusion: The evaluation items for adolescent dietary habits and nutritional practices is a useful checklist for easily and quickly assessing the dietary qualities and reflecting Korean adolescents and their food environmental factors related to a sustainable diet.

• Journal of Sasang Constitutional Medicine
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• v.8 no.1
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• pp.247-294
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• 1996

By means of the statistical data which has been collected with newly revised QSCC made use of the outpatient group examined at Kyung-Hee Medical Center and an open ordinary person group, the author proceeded statistical analysis for the validation study of the revised questionnaire itself. First, check the accurate discrimination rate by performing discriminant analysis on the statistical data of the patient group. And next, sought T-score by applying the norms gained in process of standadization of the open ordinary person group to the Sasang scale score of the outpatient group and investigated the distinctive feature between the subpopulations which was devided in the process of multivarite cluster analysis. The result was summarized as follows ; 1. The validity of the questionnaire was established through the fact that the accurate discrimination rate the ratio between predicted group and actual group was figured out 70.08%. 2. At the profile analysis the response to the relevant scale showed notable upward tendency in each constitutional group and therefore it seems to be pertinent in the field of constitutional discrimination. 3. In the observation of the power of expression through the profile analysis of each constitutional group the Soyang group demonstrated the most remarkable outcome, the Soeum group was the most inferior and the Taieum group revealed a sort of dual property. 4. What is called the group of seceder out of three subpopulation of each constitutional group distinguished definitely from the contrasted groups at the point of the distinctive profile feature and the content is like following description. (1) The seceder group of Soyang-in showed considerably passive disposition differently from general character of ordinary Soyang group and an appearance attracting the attention is that they demonstrated comparatively higher response at Soeum scale (2) The seceder group of Taieum-in gained low scores in general that informed the passive disposition of the group and the other way of the general property of Taieum group which showed accompanied ascension in Taiyang-Taieum scales they demonstrated sharply declined score at Taiyang scale (3) The seceder group of Soeum-in demonstrated distinctive property similar to the profile feature of Soyang group and it notifies that the passive property of Soeum group was diluted for the most part. According to the above result, the validity of newly revised questionnaire has been proven successfully and the property of seceder groups could be noticed to some degree through the profile analysis on the course of this study. The result of this study is expected to use as a research materials to produce next edition of the questionnaire and it is regarded that further inquisition about the difference between the seceder group and the contrasted group is required for the promotion of the questionnaire as it refered several times in the contents of the main discourse.

• Journal of Hospice and Palliative Care
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• v.1 no.1
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• pp.56-64
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• 1998

Purpose : Seoul National University Hospital developed a group counseling program for the terminal cancer patients and their family members. This program consists of each of doctor, nutritionist, nurse, pharmacist, and social worker to provide them with the information and to enhance their ability to cope with terminal cancer. This research aims to introduce this new program per se, and to appreciate its validity and applicability to the terminal cancer patients and their family members by analyzing the concerns and specific questions of the participants. Methods : The methodological approach employed in this research is 1996 content analysis of the group counseling reports, and interview of the 312 participants. The analysis includes the general characteristics of the subjects, family relationship to the patients, times of attendance to the group session, source of information to the program. Results : The participants consist of 261 family members(84%) and 51 patients(16%). Majority responded to the program with a single-attendance. Diagnosis are mainly lung cancer, stomach cancer, liver cancer. The ratio of participants by family members is decreased in the order of spouse, children, daughter-in-law, brothers and sisters, and parents. The source of information to the program is largely through medical staff(69%) as compared with posters in the hospital (26%). The participants are interested primarily in the medical information. Their interests are various, such as pain control, patient care, nutrition, psychosocial problem and etc. Conclusion : This program is characterized largely as a family-supporting program which primarily offers information for terminal cancer. This program is a sort of a hospice program, which maximizes the present quality of living of the terminal cancer patients as long as life continues by encouraging them to live with terminal cancer. Thus, this group program can be employed as an active support network for the patients and their family. In order to develop comprehensive care-giving services, it is required to have 24-hour telephone service, hospice facilities, home care service, and communication between the referral hospitals and the primary care physicians, in particular. Such a development of services is the ultimate goal for improving care. But the immediate goal of the program is to make possible better education for the patients and their family to live with terminal cancer.

• Therapeutic Science for Rehabilitation
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• v.9 no.1
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• pp.24-44
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• 2020

Objective : To develop an occupation-based bilateral upper extremity training protocol that can be effectively applied in a medical setting Methods : The research process using the delphi technique was carried out in 3 stages. The first stage was an open questionnaire development stage, The first draft is prepared through literature review and open questions were developed through preliminary research based on the draft. The second stage was the delphi survey. Based on the responses of the experts obtained through the open Delphi survey, the adequacy of the training protocol was shown on a Likert 5 point scale. The items were edited and deleted, reconstructed by analyzing the mean and standard deviation, stability, convergence degree, consensus, and content validity ratio through the questionnaire. The third step was the completion of the protocol. After discussions between researchers, the finalized protocol contents were reorganized to complete the occupation-based bilateral upper extremity training protocol for medical setting. Results : The final protocol consisted of 9 items across 3 areas in the occupation-based intervention selection domain and 81 items across 4 areas in the bilateral upper extremity training domain, intervention period, and evaluation. Conclusions : This study suggests an evidence-based method that collects the opinions of occupational therapists in order to use occupation-based activities as interventions in a situation that currently sees occupational therapy primarily performed in hospitals. It is also meaningful that the bilateral upper extremity training can be applied effectively in clinical situations by concretely presenting.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.529-538
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• 2020

This study aims to develop of contents for the activities of daily living training - Korean version that reflexes the domestic situation and can be applied to clinical practice. For contents development, a Delphi survey was conducted with 13 experts. In the first Delphi survey, 133 items of activities of daily living training are derived based on previous studies, and then the extracted items are asked to group of experts, and the derived items are answered for actual domestic clinical application. In the second survey, 118 items were added by excluding items with a low content validity ratio (CVR) including the results of the first survey, and adding items that can be derived from other opinions. In the 3rd survey, while presenting the 2nd Delphi survey items as they are, it provides an opportunity to change their opinions by presenting their 2nd response and the 2nd average score of other expert panels, and adding appropriateness and importance together. The data were analyzed to obtain the mean, standard deviation, interquartile range, CVR, convergence, and consensus. Finally, a total of 69 items were selected and 49 items were excluded so that 105 items for CVR 0.54 or higher, 111 items for convergence degree 0.50 or lower, and 70 items for continuity degree 0.75 or higher. Sexual activity, care of others, care of pets, and child rearing are difficult to apply socially and culturally, driving and community mobility cannot be performed within the clinical room, and home establishment and management may have different roles depending on gender, and religious spiritual activities and expression are so personal. For these reasons, these items were found to have low importance or suitability. This study can be usefully used as an indicator on the activities of daily living training - Korean version in clinic or community setting.