• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.203-210
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• 2020

Memory-based collaborative filtering is one of the representative types of the recommender system, but it suffers from the inherent problem of data sparsity. Although many works have been devoted to solving this problem, there is still a request for more systematic approaches to the problem. This study exploits distribution of user ratings given to items for computing similarity. All user ratings are utilized in the proposed method, compared to previous ones which use ratings for only common items between users. Moreover, for similarity computation, it takes a global view of ratings for items by reflecting other users' ratings for that item. Performance is evaluated through experiments and compared to that of other relevant methods. The results reveal that the proposed demonstrates superior performance in prediction and rank accuracies. This improvement in prediction accuracy is as high as 2.6 times more than that achieved by the state-of-the-art method over the traditional similarity measures.

• Journal of the Korea Society of Computer and Information
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• v.27 no.1
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• pp.83-89
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• 2022

As a representative technique of recommender systems, collaborative filtering has been successfully in service through many commercial and academic systems. This technique recommends items highly rated by similar neighbor users, based on similarity of ratings on common items rated by two users. Recently research on time-aware recommender systems has been conducted, which attempts to improve system performance by reflecting user rating time of items. However, the decay rate uniform to past ratings has a risk of lowering the rating prediction performance of the system. This study proposes a rating time-aware similarity measure between users, which is a novel approach different from previous ones. The proposed approach considers changes of similarity value over time, not item rating time. In order to evaluate performance of the proposed method, experiments using various parameter values and types of time change functions are conducted, resulting in improving prediction accuracy of existing traditional similarity measures significantly.

• Journal of Korean Academy of Nursing
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• v.52 no.6
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• pp.564-581
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• 2022

Purpose: This study aimed to evaluate the validity and reliability of the Korean version of the Readiness for Practice Survey (K-RPS). Method: The English Readiness for Practice Survey was translated into Korean using the Translation, Review, Adjudication, Pretesting, and Documentation (TRAPD) method. Secondary data analysis was performed using the dataset from the New Nurse e-Cohort study (Panel 2020) in South Korea. This study used a nationally representative sample of 812 senior nursing students. Exploratory and confirmatory factor analyses were also conducted. Convergent validity within the items and discriminant validity between factors were assessed to evaluate construct validity. Construct validity for hypothesis testing was evaluated using convergent and discriminant validity. Ordinary α was used to assess reliability. Results: The K-RPS comprises 20 items examining four factors: clinical problem solving, learning experience, professional responsibilities, and professional preparation. Although the convergent validity of the items was successfully verified, discriminant validity between the factors was not. The K-RPS construct validity was verified using a bi-factor model (CMIN/DF 2.20, RMSEA .06, TLI .97, CFI .97, and PGFI .59). The K-RPS was significantly correlated with self-esteem (r = .43, p < .001) and anxiety about clinical practicum (r = - .50, p < .001). Internal consistency was reliable based on an ordinary α of .88. Conclusion: The K-RPS is both valid and reliable and can be used as a standardized Korean version of the Readiness for Practice measurement tool.

• Journal of Korean Academy of Nursing
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• v.53 no.3
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• pp.359-369
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• 2023

Purpose: This study evaluated the internal structure (structural validity, internal consistency, and measurement invariance) of the Health-Related Quality of Life Instrument with Eight Items (HINT-8), developed to measure Korean people's health-related quality of life. Methods: A secondary analysis was conducted using data from the Korea National Health and Nutrition Examination Survey, involving 6,167 adults aged over 18 years. The structural validity of the HINT-8 was assessed using exploratory graph analysis and confirmatory factor analysis. Internal consistency and measurement invariance were analyzed using McDonald's omega (ω) and multigroup confirmatory factor analysis, respectively. Results: The HINT-8 had a single dimension and good internal consistency (ω =.804). The one-dimension HINT-8 exhibited matric invariance but not scalar invariance across sociodemographic groups (sex, age, education, and marital status). Further, it exhibited scalar or partial scalar invariance across medical condition groups (hypertension, diabetes, depressive symptoms, and cancer). Conclusion: The study finds that the HINT-8 demonstrated satisfactory structural validity and internal consistency, indicating its suitability for practice and research. However, the HINT-8 scores cannot be compared across different groups regarding sex, age, education, and marital status, as the interpretation varies within each sociodemographic category. Conversely, interpretation of the HINT-8 is consistent for individuals with and without hypertension, diabetes, depressive symptom, and cancer.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.251-260
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• 2000

Seismic performance evaluation systems require rational classification of structure systems, proper evaluation criteria, and their scoring index for synthesis. Current seismic performance systems need expert judgments based on collection of available data, approximate analysis of important items, and various scoring system. This study presents a three-step seismic performance evaluation system for building structures in Korea. Each evaluation step determines the seismic performance and the method depends on the degree of refinement of analysis. The preliminary step evaluation involves the global attributes of structures such as vertical irregularity, asymmetric plan, redundancy, and age of structures. The second step requires an elastic analysis for estimation of forces acting on critical sections and checks the strength and ductility. The final step requires inelastic capacity of structures. Each stephas own evaluation scheme with proper weighing factor dependent on the importance and consequence. This study applies the fuzzy theory to a scoring method that synthesizes the individual quantity to a representative value.

• Advances in aircraft and spacecraft science
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• v.5 no.2
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• pp.239-249
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• 2018

Physical tests are performed at various stages of the development cycle of a product, from prototype validation to product qualification. Although costly, there are growing demands for qualification tests like endurance vibration testing to be more representative of the real world. At the same time there are growing demands to assess the durability of these items based on FEA simulation. In this paper, we will explain how to set up a CAE-based test and how to correlate the results with some physical measurements. Specific assumptions will be explained and some advantages of using virtual tests will be highlighted such as the reduction of the number of prototypes needed, investigations on failures, evaluation of the level of reliability via sensitivity analysis, evaluation of the margins are at the end of a successful test. This presentation will therefore focus on explaining and showing how virtual tests can enrich the exploitation of physical tests.

• Language and Information
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• v.4 no.2
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• pp.107-124
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• 2000

This paper reports the syntactic distribution of amu-N-to/-ilato/-ina phrase, which are representative polarity sensitive items. (PSIs) in Korean, and ac- counts for their semantic characteristics in therms of "arbitrary choice quantification" and "concession" In the first section, we extensively illustrate the distributional behaviour of the PSIs in various costructions and roughly generalize the distribu- tion in terms of "(anti/non-) verdicality" Section 2 claims amu denotes an arbi- trary choice quantifier and the particles -to/-ilato/-ina as "concessive" markers, so the compounds denote a special element in a pragmatic scale determined by con- text/situation, Section 3. based on the pragmatics of scalar implicature, accounts for the apparent ambiguity of PSIs between "universal"and "existential"readings and further characterizes the difference among the concessive markers -to/-ilato/-ina in terms of "quantity/ quality scale."rkers -to/-ilato/-ina in terms of "quantity/ quality scale."

• Journal of information and communication convergence engineering
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• v.14 no.3
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• pp.191-199
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• 2016

In this study, we investigate the safety requirements and test methods of a radiofrequency stimulator. The main test items include controls of a minimum output, accommodation range, and output parameters that have been known as the safety requirements in conformity with international standards. As the test criteria for controlling the minimum output, an increase or decrease in a unit of 1 mA or 1 V or less was applied to the output amplitude regulator for both continuous and discontinuous control, and the output at the minimum setting was manipulated to not exceed 2% of the maximum setting. For controlling the output parameters, one of the representative test criteria states that the current limit of 250 mA should be equal to or less than 1,500 Hz. Consequently, when applying the radiofrequency stimulator on the human body, we need to ensure that the safety requirements conform to the international standards.

• Journal of Korean Library and Information Science Society
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• v.27
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• pp.369-389
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• 1997

KDC(Korea Decimal Classification), which is representative literature classification scheme in Korea, was revised and published in 1996. The purpose of this paper is to suggest a reform measure after detecting out issues and problems associated with the KDC 4th ed. through the result of lecture. The outline of suggestions are as follows : (1) There are not all items of auxiliary tables in relative index. (2) Auxiliary table 2 (Geographic Areas) is not detailed. (3) The manual for the shake of efficient usage is nonexistent and notes are poor in content. (4) Sufficient minimax and alternatives must be setted up for efficiency usage. (5) Some parts of the main schedule are disorder and not logical.

• The Journal of the Korea Contents Association
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• v.6 no.10
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• pp.80-88
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• 2006

This paper suggests frame of analysis about MMORPG and analyzes three representative games. That frame has seven categories and more divisional analysing items. The 7 categories are community orientation, PK orientation, convenient usability of item, variety of character, balance, convenience of interface, aesthetics of graphic and sound. As a result, We found that Lineage and WOW have many different characters and Ragnarok has the characters in-between Lineage and WOW.