• Journal of Korean Library and Information Science Society
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• v.36 no.2
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• pp.49-68
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• 2005

The purpose of this study is to examine the research trends and their experiment results on the applications of the language models for information retrieval. We reviewed the previous studies with the following categories: (1) the first generation of language modeling information retrieval (LMIR) experiments which are mainly focused on comparing the language modeling information retrieval with the traditional retrieval models in their retrieval performance, and (2) the second generation of LMIR experiments which are focused on comparing the expanded language modeling information retrieval with the basic language models in their retrieval performance. Through the analysis of the previous experiments results, we found that (1) language models are outperformed the probabilistic model or vector space model approaches, and (2) the expended language models demonstrated better results than the basic language models in their retrieval performance.

• The Journal of Korean Medicine
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• v.27 no.1 s.65
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• pp.57-77
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• 2006

Objectives : The purpose of this study is to review research papers published by Korean research groups on biophoton of human beings based on experiment subject and methodology. Methods : In order to review human biophoton research executed in Korea, all the papers published in Korean and international journals by Korean research groups were selected. Several key foreign papers were also reviewed for clarification of this study. Based on experiment subjects, experiment methodology, and interpretation of experiment results were analyzed. On each experiment, its original interpretation was directly quoted. Issues on the experiment methodology and interpretation were expressed at the end of each subject. Results and Conclusions : We found that experiments on human biophoton were compelling. However it seemed that more experiments, especially on their sample sizes, are needed to demonstrate its clinical application. Interpretations based on Korean traditional medicine also need to be elaborated more. In order to do accomplish clinical application of biophoton, interdisciplinary works are required. Some suggestions on biophoton experiments were made.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.27-35
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• 2003

Because of the lack of translation invariance of wavelet basis, traditional wavelet thresholding denoising leads to pseudo-Gibbs phenomena in the vicinity of discontinuities of signal. In this paper, in order to reduce the pseudo-Gibbs phenomena, wavelet coefficients are thresholded and reconstruction algorithm is implemented through minimizing the total variation of denoising signal using subgradient descent algorithm. Most of experiments were performed under the non-real-time and real-time environments. In the case of non-real-time experiments, the algorithm that this paper proposes was found more effective than that of wavelet hard thresholding denoising by 2.794㏈(SNR) based on the signal to noise ratio. And lots of pseudo-Gibbs phenomena was removed visually in the vicinity of discontinuities. In the case of real-time experiments, the number of iteration was restricted to 60 times considering the performance time. It took 0.49 seconds and most of the pseudo-Gibbs phenomena were also removed.

• Journal of the Korean School Mathematics Society
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• v.11 no.3
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• pp.439-466
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• 2008

In this paper, we aim to draw up an alternative instruction scheme by designing a web based instruction model on mathematics. Some learning materials are developed according to the scheme, and its educational effects are examined when it is committed to through regular curriculum. The study is composed of three major parts; setting of the theoretical foundation on cultivating Web based educational materials, design and composition of Web based teaching-learning model, and its experiments in the regular class. First of all, we are concerned with the core principles on WBI including the learning theories, developing learner oriented instruction model, design as well as build-up process for education materials, and strategy in instruction. Next, we propose an alternative instruction model for mathematics, in which programs to embody mathematics education and instruction on the Web are constructed, on the while, the study is proceeded through the Web Site. Finally, we design and produce a WBI instruction model on the subject of the plane quadratic curves. This model is examined in the regular class to estimate its educational effects compared with traditional teaching standpoints. Concomitantly, we explore essential elements and the direction of future growth associated with the Web oriented education.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.305-315
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• 2020

The purpose of this study is to compare algorithms of single photo resection, which determines the exterior orientation parameters used in fields such as photogrammetry, computer vision, robotics, etc. To this end, the algorithms were compared by generating experimental data by simulating terrain based on a camera used in aerial and close-range photogrammetry. Through experiments on aerial photographic camera that was taken almost vertically, it was possible to determine the exterior orientation parameters using three ground control points, but the Procrustes algorithm was sensitive to the configuration of the ground control points. Even in experiments with a close-range amateur camera where the attitude angles of the camera change significantly, the algorithm was sensitive to the configuration of the ground control points, and the other algorithms required at least six ground control points. Through experiments with two types of cameras, it was found that cosine lawbased spatial resection shows performance similar to that of a traditional photogrammetry algorithm because the number of iterations is short and no explicit initial values are required.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.1
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• pp.50-60
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• 2013

High temperature proton exchange membrane fuel cells (PEMFCs) using phosphoric acid (PA) doped polybenzimidazole (PBI) membranes have been concentrated as one of solutions to the limits with traditional low temperature PEMFCs. However, the amount of reported experimental data is not enough to catch the operational characteristics correlated with cell performance and durability. In this study, design of experiments (DOE) based operational optimization method for high temperature PEMFCs has been proposed. Response surface method (RSM) is very useful to effectively analyze target system's characteristics and to optimize operating conditions for a short time. Thus RSM using central composite design (CCD) as one of methodologies for design of experiments (DOE) was adopted. For this work, the statistic models which predict the performance and degradation rate with respect to the operating conditions have been developed. The developed performance and degradation models exhibit a good agreement with experimental data. Compared to the existing arbitrary operation, the expected cell lifetime and average cell performance during whole operation could be improved by optimizing operating conditions. Furthermore, the proposed optimization method could find different new optimal solutions for operating conditions if the target lifetime of the fuel cell system is changed. It is expected that the proposed method is very useful to find optimal operating conditions and enhance performance and durability for many other types of fuel cell systems.

• Smart Structures and Systems
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• v.18 no.3
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• pp.601-623
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• 2016

Precast concrete elements are widely used in the construction of buildings and civil infrastructures as they provide higher construction quality and requires less construction time. However, any abnormalities in precast concrete surfaces such as non-flatness or distortion, can influence the erection of the elements as well as the functional performance of the connections between elements. Thus, it is important to undertake surface flatness and distortion inspection (SFDI) on precast concrete elements before their delivery to the construction sites. The traditional methods of SFDI which are conducted manually or by contact-type devices are, however, time-consuming, labor-intensive and error-prone. To tackle these problems, this study proposes techniques for SFDI of precast concrete elements using laser scanning technology. The proposed techniques estimate the $F_F$ number to evaluate the surface flatness, and estimate three different measurements, warping, bowing, and differential elevation between adjacent elements, to evaluate the surface distortion. The proposed techniques were validated by experiments on four small scale test specimens manufactured by a 3D printer. The measured surface flatness and distortion from the laser scanned data were compared to the actual ones, which were obtained from the designed surface geometries of the specimens. The validation experiments show that the proposed techniques can evaluate the surface flatness and distortion effectively and accurately. Furthermore, scanning experiments on two actual precast concrete bridge deck panels were conducted and the proposed techniques were successfully applied to the scanned data of the panels.

• Journal of The Korean Association For Science Education
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• v.22 no.4
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• pp.757-767
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• 2002

This study investigated the effects of scientific inquiry experiments emphasizing social interaction on the academic achievement, the ability for science inquiry and the learning motivation of the students. To examine the differences among the classes of scientific inquiry experiments according to the way of organizing small groups, the effects of the group in homogeneous cognitive level and the group in heterogeneous cognitive level were compared. 255 7th-graders were grouped into the treatment group and the control group. After the treatment group received the scientific inquiry experimental lessons emphasizing social interaction and the control group received traditional lessons for one year, academic achievement, ability for scientific inquiry, and learning motivation were examined. These inquiry experiments were composed of four steps which are eliciting, familiarizing, constructing and bridging. And students can interact with peers and teachers through the process of relating observed phenomena to concept, constructing experiment procedure, and eliciting results. The ANCOVA results revealed that there were significant effects of science inquiry experiments emphasizing social interaction on the academic achievement, the ability for scientific inquiry and the learning motivation of the students. The significant academic achievement of the students in most of the cognitive levels, if not all, was found and degree of improvement in the ability for scientific inquiry was lower than that in the academic achievement. Concerning the effects according to the way of organizing small groups, there were significant improvement in academic achievement and learning motivation of the group in homogeneous cognitive level compared to the group in heterogeneous cognitive level. These results indicate that social interaction in learning is important and it has positive influences on the improvement in academic achievement and ability for scientific inquiry of students.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.470-480
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• 2001

The purpose of this study was to investigate the effects of science inquiry experiments emphasizing social interaction on the development of process skills of the students. The social interactions by cognitive level of the students were also analyzed. For this study, 197 8th grade students were sampled. They were divided into an experimental group and a control group. During four-month period, the experimental group received science inquiry experiments treatment emphasizing social interactions while the control group received traditional treatment. Not only science inquiry ability pretest-posttest, but also multiple data collection method such as a questionnaire, class observation, and audio/video recording were used in collecting the data. According to the results of this study, it was found that the mean score of the experimental group was significantly higher than that of the control group at 0.05 level. It was also found that the students of high cognitive level led the peers and participated in the class discussion actively with the teacher while the students of low cognitive level followed the students of high cognitive level and showed inactive interaction with the teacher. Analysis of the students' perceptions on inquiry experiments showed that students participated in discussion actively in the class as these experiments gave an opportunity for them to discuss and were able to solve the problems with peers' help through discussion.

• Journal of the HCI Society of Korea
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• v.7 no.2
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• pp.25-34
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• 2012

A veterinary student learns and experiences veterinary processes though experiments and practices using real animals. However, animal protection laws regulate animal experiments and restrict number of the experiments on laboratory animals, veterinary students would have less chances of the experiments and the practices for their veterinary training with real animals. This paper proposes a simulator for veterinary education based on augmented reality (AR). We selected an intravenous injection procedure for the simulation because the injection procedure is the most frequently used procedure during veterinary training and the most difficult stage for beginning veterinary students. The proposed AR simulator provides with a tangible prop, of which shape looks like a leg of a real dog. It also has a injection simulator, which receives user's input and sends force feedbacks to indicate results of the injection simulation. We developed a WorkBench type AR system with an LED display and cameras for visual information processing. Finally, we evaluated its performance through experiments and user studies to check its acceptance level and usability of the proposed system. We compared the proposed system with a traditional video based education and an AR based system using a head mounded display (HMD). The results that the proposed system showed better performances over these systems.