• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.1
• /
• pp.185-191
• /
• 2004

This article is concerned with cloth wearing system issues arising in the computer graphics. In particular, we study the issues of fabric drape properties for representing cloth wearing system. The convex points based on distance function are calculated to represent useful fabric drape properties. The information such as perimeter area, max and min point among convex point, the average distance between convex points are extracted. A strategy of a circularity based on the perimeter and area is considered for fabric drape property measurement. By experimental result, the circularity is most powerful factor to represent the drape property among the several characteristics. The measured drape properties will contribute to cloth wearing system development.

• Journal of Information Science Theory and Practice
• /
• v.8 no.2
• /
• pp.68-78
• /
• 2020

This study is a preliminary study to develop an evaluation framework necessary for evaluating the DataON platform. The first objective is to examine expert perceptions of the level of DataON platform construction. The second objective is to evaluate the importance, stability, and usability of DataON platform features over OpenAIRE features. The third objective is to derive weights from the evaluation perspective for future DataON platform evaluation. The fourth objective is to examine the preferences of experts in each evaluation perspective and to derive unbiased evaluation criteria. This study used a survey method for potential stakeholders of the DataON platform. The survey included 12 professionals with at least 10 years of experience in the field. The 57 overall functions and services were measured at 3.1 out of 5 for importance. Stability was -0.07 point and usability was measured as -0.05 point. The 42 features and services scored 3.04 points in importance. Stability was -0.58 points and usability was -0.51 points. In particular, the stability and usability scores of the 42 functions and services provided as of 2018 were higher than the total functions were, which is attributed to the stable and user-friendly improvement after development. In terms of the weight of the evaluation point, the collection quality has the highest weight of 27%. Interface usability is then weighted 22%. Subsequently, service quality is weighted 19%, and finally system performance efficiency and user feedback solicitation are equally weighted 16%.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.8
• /
• pp.471-480
• /
• 2003

The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. Among the reasons for its complexity are the system size, conflicting requirements of estimator accuracy, reliability in the presence of transducer noise and data communication failures, adaptability to change in the network topology and cost minimization. In particular, the number of harmonic instruments available is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs) which is widely used in areas such as: optimization of the objective function, learning of neural networks, tuning of fuzzy membership functions, machine learning, system identification and control. This HSE has been applied to the Simulation Test Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using Genetic Algorithms (GAs) in the Harmonic State Estimation (HSE).

• Journal of the Korean Mathematical Society
• /
• v.56 no.6
• /
• pp.1561-1597
• /
• 2019

In this paper we introduce the notions of topological entropy and topological pressure for non-autonomous iterated function systems (or NAIFSs for short) on countably infinite alphabets. NAIFSs differ from the usual (autonomous) iterated function systems, they are given [32] by a sequence of collections of continuous maps on a compact topological space, where maps are allowed to vary between iterations. Several basic properties of topological pressure and topological entropy of NAIFSs are provided. Especially, we generalize the classical Bowen's result to NAIFSs ensures that the topological entropy is concentrated on the set of nonwandering points. Then, we define the notion of specification property, under which, the NAIFSs have positive topological entropy and all points are entropy points. In particular, each NAIFS with the specification property is topologically chaotic. Additionally, the ${\ast}$-expansive property for NAIFSs is introduced. We will prove that the topological pressure of any continuous potential can be computed as a limit at a definite size scale whenever the NAIFS satisfies the ${\ast}$-expansive property. Finally, we study the NAIFSs induced by expanding maps. We prove that these NAIFSs having the specification and ${\ast}$-expansive properties.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.1146-1153
• /
• 2022

As the population is aging, accidents involving elderly people are also increasing (2014:11,667 persons; 2018: 11,797 persons). In the case of the elderly population, falling accidents are the primary direct or indirect causes of death; in particular, they face an elevated risk of staircase falls. This study proposes a method of evaluating the safety of staircases using Building Information Modeling (BIM)-based virtual simulation. By making a virtual user with the behavioral characteristics of the elderly respond to a staircase in a BIM model, its safety performance can be evaluated. The evaluation criteria were derived from regulations, elements, and characteristics relevant to the safety of staircases. To validate the proposed method, safety evaluation tests were simulated on actual staircases. The evaluation result of the test simulation shows the safety scores of 1.97 points for the elderly user and 2.95 points for the average male adult user against a required safety score of a minimum of 2 points. That is, safety is relative to users as the safety of the same staircase can be different depending upon the different behavioral characteristics of users. The study suggests that the risk of staircase-related fall accidents to the elderly can be reduced by improving staircase designs through the proposed method.

• Journal of Korean Society for Quality Management
• /
• v.31 no.2
• /
• pp.17-39
• /
• 2003

The 21st century is called “an era of creation” or “an era of speed.” These are flat expressions requiring a fierce competition between individuals, corporations and nations. In a reality in which we should make new things continuously within a short period of time, the world best benchmarking can become a good alternative. The world best practice can be called “a mode of operation” that has created the world's best performance in a particular field of managerial activities. It is very meaningful for the nations' corporations, which have a lower competitiveness than world-class ones and weak points in the area of human resources development, in particular, to benchmark the world-class corporations' best practices of HRD. Therefore, this study is conducted in conformity with a model of the Instructional Systems Designs for the Total Quality Education that brings the structure of the world-class corporations' best practices of HRD into line with that of the Total Quality Management. That is, analysis, design, development, implementation and assessment are included in this study.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.31B no.4
• /
• pp.88-96
• /
• 1994

In this paper, we propose a subband pyramid image coding scheme that uses ECVQ (ntropy Constrained Vector Quantizer). In subband pyramid image coding, each subband can be encoded with a coder matched to the statistics of that particular subband, and available versions of the original image at different resolution are easily obtained. ECVQ, aiming at the minimization of the distortion for a fixed entropy of the quantizer output, is well combined with the subband pyramid image coding which yields high compression ratio and good image quality. The optimum bit allocation to each subbands corresponds to the points where the individual distortion rate curves are of particular slope, weighted to the number of samples in that subband, in designing ECVQ.

• Journal of Information Processing Systems
• /
• v.14 no.4
• /
• pp.877-891
• /
• 2018

In this paper, we propose a novel algorithm for rendering motion-blurred shadows utilizing a depth-time ranges shadow map. First, we render a scene from a light source to generate a shadow map. For each pixel in the shadow map, we store a list of depth-time ranges. Each range has two points defining a period where a particular geometry was visible to the light source and two distances from the light. Next, we render the scene from the camera to perform shadow tests. With the depths and times of each range, we can easily sample the shadow map at a particular receiver and time. Our algorithm runs entirely on GPUs and solves various problems encountered by previous approaches.

• SUVANNABHUMI
• /
• v.10 no.1
• /
• pp.93-116
• /
• 2018

Under feudalism, besides imploring investiture, tribute is said to be one of the two most typical activities at the core of diplomatic relations between China and the region, in particular, Vietnam and Japan. By using the comparative method and interdisciplinary approach, the author shows that there are many differences between Vietnam and Japan with regards to tribute activity with China during the feudal period. For example, the start and end of China's tributary activities with Vietnam and Japan are not the same. The period of Japanese tributary activity was much more loosened than Vietnam. Vietnamese tributary relation was political, while Japan placed economic benefits as the main priority. In particular, the author also proved that although Japan and China had differences in behavior and level of dependence on the tributary activity of Vietnam, both Vietnam and Japan maintained independence and autonomy. Based on the historical, cultural, and geographical characteristics, as well as the position and force correlation of each country in relation to China, this article also explains the causes of these similarities and differences.

• Journal of Pharmaceutical Investigation
• /
• v.33 no.3
• /
• pp.245-253
• /
• 2003

Dissolution profile comparsions can be done by virtue of the similarity factor $(f_2)$. It is a logarithmic reciprocal square root transformation of the sum of squared error of % dissolution differences between two profiles at several time points. It gives information on the degree of similarity between the two profiles: An $f_2$ value between 50 and 100 suggests the similarity/equivalence of the two dissolution curves being compared. The objective of this report was to provide a careful examination on the $f_2$ metrics in detail. It was shown that $f_2$ values exceeded 50, when relative differences in % dissolved between two products were less than 15% at all time points. The similarity factor value was also found to be greater than 50, in cases when absolute % dissolution differences were below 10% at all time points. Interestingly, the $f_2$ value was changed by the number of the time points selected for calculation. In particular, $f_2$ tended to have higher values, when the $f_2$ metrics used a large number of time points in which % dissolved reached plateau. Finally, since the similarity factor was a sample statistics, it was impossible to infer type I/II errors and sampling error. Despite certain limitations inherited in the $f_2$ metrics, it was easy and convenient to evaluate how similar the two dissolution profiles were.