• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.3
• /
• pp.254-260
• /
• 2019

Recently, the importance of signal processing has become gradually significant, as the frequency of video media increases in various fields. However, numerous kinds of noise generated in the transmission and reception processes can possibly affect the signal information, and the noise removal is for that reason essential as a preprocessing step. In this paper, we propose an algorithm to remove the mixed noise which is composed of impulse noise and AWGN. This algorithm is used for image restoration by noise judgment for efficient noise removal in a complex noise environment, and the noise is removed by considering spatial characteristics and pixel variations. Simulation results show that unlike existing methods, the algorithm has excellent noise cancellation characteristics by minimizing both noise effects and consequently eliminating the mixed noise; for objective judgment, we compared and analyzed the data using PSNR and profile.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.4
• /
• pp.394-400
• /
• 2019

Noise removal is one of the required step in processing digital video and there are many researches to develop algorithm that fits with its purpose and environment. However, present impulse noise removal methods are lacking in its function in terms of removing noise in edge and high frequency factors. Therefore, this research has Extended range of masks depending on density to determine noise so that high frequency factors can be preserved. The range of resolution is set based on median and standard deviation of inside resolution after removing impulse noise. afterwards, those resolution within the range are calculated by adding weight to have the final output value. The suggested algorithm has an enhanced function in removing noise in various areas with many edge and high frequency factors than present methods and their functions are compared through simulation.

• The Journal of Advanced Prosthodontics
• /
• v.11 no.2
• /
• pp.120-127
• /
• 2019

PURPOSE. To determine wear amount of single molar crowns, made from four different restoratives, and opposing natural teeth through computerized fabrication techniques using 3D image alignment. MATERIALS AND METHODS. A total of 24 single crowns (N = 24 patients, age range: 18 - 50) were made from lithium disilicate (IPS E-max CAD), lithium silicate and zirconia based (Vita Suprinity CAD), resin matrix ceramic material (Cerasmart, GC), and dual matrix (Vita Enamic CAD) blocks. After digital impressions (Cerec 3D Bluecam, DentsplySirona), the crowns were designed and manufactured (Cerec 3, DentsplySirona). A dualcuring resin cement was used for cementation (Variolink Esthetic DC, Ivoclar). Then, measurement and recording of crowns and the opposing enamel surfaces with the intraoral scanner were made as well as at the third and sixth month follow-ups. All measurements were superimposed with a software (David-Laserscanner, V3.10.4). Volume loss due to wear was calculated from baseline to follow-up periods with Siemens Unigraphics NX 10 software. Statistical analysis was accomplished by Repeated Measures for ANOVA (SPSS 21) at = .05 significance level. RESULTS. After 6 months, insignificant differences of the glass matrix and resin matrix materials for restoration/enamel wear were observed (P>.05). While there were no significant differences between the glass matrix groups (P>.05), significant differences between the resin matrix group materials (P<.05) were obtained. Although Cerasmart and Enamic were both resin matrix based, they exhibited different wear characteristics. CONCLUSION. Glass matrix materials showed less wear both on their own and opposing enamel surfaces than resin matrix ceramic materials.

• Progress in Medical Physics
• /
• v.32 no.1
• /
• pp.18-24
• /
• 2021

Purpose: Kilovoltage computed tomography (kV-CT) is essential for radiation treatment planning. However, kV-CT images are significantly distorted by artifacts when a metallic prosthesis is present in the patient's body. Thus, the accuracies of target delineation and treatment dose calculation are inevitably lowered. We evaluated the accuracy of the calculated doses using an image restoration method with hybrid CT, which was introduced in our previous study. Methods: A cylindrical phantom containing four metals, namely, silver, copper, tin, and tungsten, was scanned using kV-CT and megavoltage CT to produce hybrid CT images. We created six verification plans for three head and neck patients on kV-CT and hybrid CT images of the phantom and calculated their doses. The actual doses were measured with film patches during beam delivery using tomotherapy. We used the gamma evaluation method to compare dose distribution between kV-CT and hybrid CT with three gamma criteria, namely, 3%/3 mm, 2%/2 mm, and 1%/1 mm. Results: The gamma pass rates decreased as the gamma criteria were strengthened, and the pass rate of hybrid CT was higher than that of kV-CT in all cases. When the 1%/1 mm criterion was used, the difference in gamma pass rates between them was up to 13%p. Conclusions: According to our findings, we expect that the use of hybrid CT can be a suitable approach to avoid the effect of severe metal artifacts on the accuracy of dose calculation and contouring.

• Journal of Korean Society of Forest Science
• /
• v.100 no.4
• /
• pp.698-707
• /
• 2011

Over the past 10 years, South Korea has implemented various plantation projects including the Pine Restoration Project in Tujiin Nars and the desertification prevention forestation in Lun soum. This study has evaluated the implementation feasibility on the small-scale A/R CDM projects in Mongolia through which carbon emission credits can be secured. Characteristics, pros and cons, economic feasibility, and project execution feasibility were compared among three possible sites, Khyalganat, Tujiin Nars, and Lun soum. Among the three evaluated sites, Tujiin Nars has the better condition in tree growth, economic feasibility, and the applicability of experience than the other two sites. A/R CDM project in Mongolia, which has a great environmental benefit of combating desertification, is expected to have some effectiveness such as lowering costs from credit benefit, sustainable management by villagers, contribution to communities, investor's contribution to society and achievement of green image, and strengthening forestry cooperation between Korea and Mongolia.

• Journal of Family Relations
• /
• v.21 no.4
• /
• pp.119-140
• /
• 2017

Objectives: The purpose of this study is to investigate and confirm the main factors of IMAGO relationship therapy(IRT) which influences overcoming a crisis of divorce, the role of the Imago relationship therapist and the changes made by the couple themselves in the process of the therapy. Method: This case study was based on the interviews with a couple who had participated in ten sessions of IRT. The couple who had been in the middle of a divorce lawsuit withdrew their suit after the therapy. The Interviews were conducted twice on the couple. The data from the interviews were analyzed by using constant comparative analysis, open coding method and Miles & Huberman's network display. Results: The findings of the study were as follows. Firstly, the factors influencing overcoming a crisis of divorce included preparation for the Imago dialogue and the structure of the Imago dialogue. Secondly, the role of the therapist was providing safety and confidence, deepening couple's conversations, and building the connectedness of the couple. Thirdly, the changes evident after the therapy included awareness of the influence of the original family, new image formation for each spouse, intimacy restoration and a changed perspective. Conclusions: Based on the findings, the study can contribute to healthy relational progress of married couples in conflict by developing the conditions to effectively apply the IRT. In addition, this study can be used to equip therapists with necessary tools and abilities for the therapy.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.21 no.3
• /
• pp.165-176
• /
• 2011

In this paper, we examine the reliability verification procedure of evidence analysis tools for computer forensics and test the famous tools for their functional requirements using the verification items proposed by standard document, TIAK.KO-12.0112. Also, we carry out performance evaluation based on test results and suggest the way of performance improvement for evidence analysis tools. To achieve this, we first investigate functions that test subjects can perform, and then we set up a specific test plan and create evidence image files which contain the contents of a verification items. We finally verify and analyze the test results. In this process, we can discover some weaknesses of most of analysis tools, such as the restoration for deleted & fragmented files, the identification of the file format which is widely used in the country and the processing of the strings composed of Korean alphabet.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.3
• /
• pp.162-172
• /
• 2022

PURPOSE. The present study aims to analyze the effect of abutment neck taper and types of cement on the amount of undetected remnant cement of cement-retained implant prostheses. MATERIALS AND METHODS. Three neck taper angles (53°, 65°, 77°) and three types of cement (RMGI: resin-modified glass ionomer, ZPC: zinc phosphate cement, ZOE: zinc oxide eugenol cement) were used. For each group, the surface percentage was measured using digital image and graphic editing software. The weight of before and after removing remnant cement from the abutment-crown assembly was measured using an electronic scale. Two-way ANOVA and Duncan & Scheffe's test were used to compare the calculated surface percentage and weight of remnant cement (α = .05). RESULTS. There were significant differences in remnant cement surface percentage and weight according to neck taper angles (P < .05). However, there were no significant differences in remnant cement surface percentage and weight on types of cement. No interaction was found between neck taper angles and types of luting cement (P > .05). The wide abutment with a small neck taper angle showed the most significant amount of remnant cement. And the types of luting cement did not influence the amount of residual cement. CONCLUSION. To remove excess cement better, the emergence profile of the crown should be straight to the neck taper of the abutment in cement-retained implant restoration.

• The Journal of the Korea Contents Association
• /
• v.22 no.4
• /
• pp.47-57
• /
• 2022

Newtro is gaining popularity recently as one of the media content genres. Newtro contents are not just a restoration, but are the creations that create new values by adapting to the current situation and appealing to the nostalgia for the past. A total of 254 people participated the online survey. Result showed that users prefer Newtro content that is in the 'moderate incongruity' state with moderate novelty, rather than content that is very new or too familiar. In addition, both 'personal nostalgia' from direct past experiences and 'vicarious nostalgia' from indirect experiences were found to have a positive effect on preference for Newtro content. Finally, it was confirmed that the image of Newtro contents affected the purchase intention of Newtro contents positively. But the attitude toward Newtro contents did not. Based on these results, this study suggested the implications for the differentiation strategy of Newtro contents.

• Imaging Science in Dentistry
• /
• v.52 no.3
• /
• pp.303-308
• /
• 2022

Purpose: This technical report aims to describe and detail the use of micro-computed tomography for a reliable evaluation of the bulk-fill composite/tooth interface. Materials and Methods: Bulk-fill composite restorations in tooth cavities were scanned using micro-computed tomography to obtain qualitatively and quantitatively valuable information. Two-dimensional information was processed using specific algorithms, and ultimately a 3-dimensional (3D) specimen reconstruction was generated. The 3D rendering allowed the visualization of voids inside bulk-fill composite materials and provided quantitative measurements. The 3D analysis software VG Studio MAX was used to perform image analysis and assess gap formation within the tooth-restoration interface. In particular, to evaluate internal adaptation, the Defect Analysis addon module of VG Studio Max was used. Results: The data, obtained with the processing software, highlighted the presence and the shape of gaps in different colours, representing the volume of porosity within a chromatic scale in which each colour quantitatively represents a well-defined volume. Conclusion: Micro-computed tomography makes it possible to obtain several quantitative parameters, providing fundamental information on defect shape and complexity. However, this technique has the limit of not discriminating materials without radiopacity and with low or no filler content, such as dental adhesives, and hence, they are difficult to visualise through software reconstruction.