• The korean journal of orthodontics
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• v.53 no.3
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• pp.163-174
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• 2023

Objective: This study evaluated the influence of various gingival displays on the esthetic perception in the presence of upper dental midline discrepancy. Methods: A smiling image of a male subject was altered digitally to produce five image series: normal smile (series A), decreased tooth show (series B), increased gingival show (series C), maxillary cant (series D), and asymmetric upper lip elevation (series E). In each image series, the midline was deviated to the right and left incrementally. A total of 210 raters (four professional groups and laypersons, n = 42 in each group) determined the midline deviation threshold and the attractiveness of midline position in each series. Results: The right and left thresholds were statistically similar for the symmetrical series (A, B, and C), while for series D, the right threshold was significantly lower. In most rater groups, the mean threshold order was: B > A > E > C > D. In all the series, the raters selected the coincident midline as the most attractive series except for series D, for which 1-2-mm deviations to the left were selected as the most attractive by almost all the groups. Conclusions: It is crucial to establish the coincident midline position in a symmetrical smile, especially when a gummy smile exists. In the asymmetrical gingival show, a coincident midline might not be the most esthetic midline position.

• Journal of the HCI Society of Korea
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• v.8 no.2
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• pp.21-27
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• 2013

Recently, the use of floating hologram has increased in many different aspects, such as exhibitions, education, advertisements, and so on. Especially, the floating hologram that makes use of half-mirror is widely used. Nevertheless, half-mirror, unfortunately, cannot lead users to the perfect three dimensional hologram experience. Even though it can make the vision look to be up on the air, it does not have the capacity to display itself up on the air, which is the ultimate goal of hologram. In addition, it looks inconsistent when a real object is located behind the half-mirror in order to show the convergence of the two (object and the half-mirror). In this paper, we did the study on comparison of 3D space perception for the stereoscopic AR holography. At first, we applied stereoscopic technology to the half-mirror hologram system for the accurate and realistic AR environment. Then, the users can feel as if the real 3D object behind half-mirror and the reflected virtual image are converged much better in the 3D space. Furthermore, by using depth camera, the location and direction of graphics can be controlled to change depending on the user's point of view. This is the effective way to produce augmented stereoscopic images simply and accurately through half-mirror film without any additional devices. What we saw from the user test were applying 3D images and user interaction leads the users to have 3D spatial awareness and realism more effectively and accurately.

• Journal of Digital Contents Society
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• v.11 no.2
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• pp.177-184
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• 2010

These days, as digital producing technique has been developed, 3D imaging technique is used in high-tech computer and T.V. Also study for 3D producing technique is actively in progress. Moreover, as James Cameron's movie, 'Avatar' released in 2009 was a box office hit, the issue about 3D image came to the fore again. At this point, I decided to study the effect of the visual depth caused by the color correction during the post-production stage. The purpose of this study is to offer information about processing effective images through data about the effect of the visual depth that applies the color correction during the post-production stage. Basically, I supposed that color and contract would have effects on depth of 3D image. As a result, I could find out the changes of visual depth, space perception and sense of depth throughout the experiment. Applying this result,, I produced the 15 minutes of 3D advertisement movie and I found out that the color correction during the post-production stage was very effective for 3D depth. The left image and the right image by beam splitter based rig and parallel rig were used for this study. Also I adjusted the strong contrast by the color correction during the post-production stage after correcting convergence and visual depth during editing. As a result, I could produce images which had strong sense of space and sense of depth.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.8
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• pp.1275-1283
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• 1990

Perception of surfaces from range images plays a key role in 3-D object recognition. Recognition of 3-D objects from range images is performed by matching the perceived surface descriptions with stored object models. The first step of the 3-d object recognition from range images is image segmentation. In this paper, an approach for segmenting 3-D range images into symbolic surface descriptions using spatial Gabor filter is proposed. Since the phase of data has a lot of important information, the phase information with magnitude information can effectively segment the range imagery into regions satisfying a common homogeneity criterion. The phase and magnitude of Gabor filter can represent a unique featur vector at a point of range data. As a result, range images are trnasformed into feature vectors in 3-parameter representation. The methods not only to extract meaningful features but also to classify a patch information from range images is presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.121-130
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• 2001

This paper addresses a method for evaluating perceived velocities of the graphic module in a driving simulator. The major two graphic factors associated with perceived velocities are analyzed: they are the lateral distance between a virtual driver and an array of environmental objects and the textural density of these objects. A graphical representation of a vehicle and its surrounding environment are constructed by employing a three-dimensional tool, Pro/ENGINEER and a virtual environment, dVISE. Using the developed virtual driving environment, experiments have been carried out to formulate the relationship between velocity perception and each factor. Based on the experimental results, nonlinear regression equations are derived to show how the perceived velocities are dependent upon distance/density.

• Research in Mathematical Education
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• v.12 no.3
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• pp.193-200
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• 2008

In this study, an innovative computer support has been suggested to improve differential perception of the students. Research has been conducted on a calculus class which has 35 students. A semi-structured interview has been reported in the study. By this interview, it was tried to make differential concept more understandable by using Micro Soft Excel component of the well-known MS Office software. By this aim, students have been asked to integrate a simple function by using MS Excel. At the end of the study, it was observed that differential concept made more sense in students' minds than previous.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.5
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• pp.640-655
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• 2003

Statement of problem : The beauty has a little different meaning according to a time, culture, and nation. Purpose : This study was undertaken to determine the Korean perception of the altered upper anterior dental esthetics including the lack of symmetry, the midline deviation, the gingival exposure, the inclination of incisal plane, the type of incisal plane, and the type of gingival line. Material and Method : 670 subjects were participated in this survey. A questionnaire accompanied by 12 sets of computer-manipulated images using 3D MAX 4.2 software was used to record the ranking of the geometric preference related to the anterior esthetic discrepancies in three or four degrees of alteration. The statistical significance of the differences between the groups was determined by a one-way ANOVA and a t-test. Results : The results obtained were as follows: 1) The Korean perception of the anterior dental esthetics according to the subjects' occupation, sex, and age was most affected by occupation. 2) The masked image emphasizing the dentition and lips appeared stranger than the non-masked image at the same alteration. 3) The lack of symmetry, which was expressed as a unilateral discoloration of the tooth, showed incongruity in any teeth of the anterior dentition. The incongruity was more severe as the degree occurred closer to the midline. 4) The deviation of midline was showed more severe strangeness as the degree of deviation increased. However, more than half of the subjects did not perceive a deviation of 5mm. 5) During smiling, the exposure of the upper gingiva showed more severe incongruity as the degree of gingival exposure increased. 77% of the subjects perceived strangeness at the gingival exposure of 4.5mm. 6) The inclination of the incisal plane appeared stranger as the degree of inclination increased. 62% of subjects perceived strangeness at the $7.5^{\circ}$ inclination of the incisal plane. 7) The type of incisal plane showed increasing strangeness in the order of convex/downward, straight/horizontal, and concave/upward. 80% of subjects perceived strangeness at concave/upward. 8) The type of gingival line was showed increasing incongruity in the order of the same, a little above, and a little under the zenith of the lateral incisor to the line joining the zenith of the central incisor and the canine. However, less than half the subjects did not perceive strangeness at any alteration of the gingival line. Conclusion : The Korean perception of the upper anterior dental esthetics was different to the westerner's perception in the some respects.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.31-39
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• 2015

2D-to-3D video conversion vests 3D effects in a 2D video by generating stereoscopic views using depth cues inherent in the 2D video. This technology would be a good solution to resolve the problem of 3D content shortage during the transition period to the full ripe 3D video era. In this paper, a low-complexity depth generation method for 2D-to-3D video conversion is presented. For temporal consistency in global depth, a pattern-based depth generation method is newly introduced. A low-complexity refinement algorithm for local depth is also provided to improve 3D perception in object regions. Experimental results show that the proposed method outperforms conventional methods in terms of complexity and subjective quality.

• Journal of Korean Academy of Nursing Administration
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• v.6 no.2
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• pp.259-279
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• 2000

This study is a descriptive analytic research measuring nursing service quality, using SERVQUAL model, to make fundamental data and strategies for nursing service improvement. Data were collected by self-reported questionnaire from 202 patients and 142 nurses, from June 7 to 14, 1999. The reliability of instrument were adequate(Cronbach ${\alpha}=.94$). SAS program was utilized for statistical analysis of collected data. The results were as follows; 1. There was a gab between patient's expectation and perception on nursing service(Gap B). Gap D was indicated an affecting factor to decide nursing service quality. Gap C was indicated an indirect affecting factor of nursing service quality. Because it was not statistically significant in total item analysis, but in individual item analysis, 7 items were appeared statistically significant. Gap A was not a gap occurrence factor of nursing service quality. 2. Focuses of nursing service quality improvement strategies were; (1) to direct qualitative improvement of nursing service in order to correspondence patient's nursing service expectation. (2) to make nurse's service activity modified because nurse's practice were not reached patient's expectation level. (3) to need internal, external factor analysis affecting nurse's service activity. 3. Nursing service quality was decided by rather environmental inappropriateness provided nursing service than itself. Therefore, to make nursing service quality improvement, it is required to improve nursing service environment. For this, followings are required; (1) to strengthen nurse's education on lower part of nursing service satisfaction and QI activities. (2) to balance demand and supply of nursing personnel. 3) to fix computerized system for reducing other duties weight except nursing care through analysis of nursing activity. (4) to construct rational cooperating system among related departments. 4. The important parts for nursing service quality improvement were indicated as follows: (1) Gap B: 'prompt reaction', 'examination symptom before patient's complaint', 'hearted nursing service reducing patient's dissatisfaction', 'explanation goals of nursing activities', 'having special Knowledge enough', 'maintenance position comfortably', 'management of patient's physical hygiene'. (2) Gap C: 'maintenance physical safety', 'explanation about hospital rules and facilities'. (3) Gap D: 'tender, safe injection and wound care'. Because above items are mostly improved through nurse's attitude change and quality improvement, it is required to establish nursing standardization and to strengthen nurse's clinical education. As the based on above results, followings are suggested; 1. SERVQUAL model is very useful to make strategies for nursing service quality improvement because it indicates multiple factors affecting hap occurrence. 2. At individual items analysis of Gap C, statistically significant 7 items appeared higher nurse's perception level than patient's perception level on nursing service were trouble perception level on nursing service quality improvement. So. it need further research to analysis about these difference occurring factors. 3. At analysis of Gap D, it is indicated that in nursing service performance process, multiple factors lowing nursing service quality were intruded. So it needs further research to analysis what these factors are and how each factors affect on nursing performance process. 4. nursing service quality measurement is changeable according to sample select time or sampled subject's characteristics. So to develope strategy for nursing service quality improvement is based on the results of periodical analysis.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.204-214
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• 2015

Depth map upsampling is an approach to increase the spatial resolution of depth maps obtained from a depth camera. Depth map quality is closely related to 3D perception of stereoscopic image, multi-view image and holography. In general, the performance of upsampled depth map is evaluated by PSNR (Peak Signal to Noise Ratio). On the other hand, time-consuming 3D subjective tests requiring human subjects are carried out for examining the 3D perception as well as visual fatigue for 3D contents. Therefore, if an objective metric is closely correlated with a subjective test, the latter can be replaced by the objective metric. For this, this paper proposes a best metric by investigating the relationship between diverse objective metrics and 3D subjective tests. Diverse reference and no-reference metrics are adopted to evaluate the performance of upsampled depth maps. The subjective test is performed based on DSCQS test. From the utilization and analysis of three kinds of correlations, we validated that SSIM and Edge-PSNR can replace the subjective test.