• Title/Summary/Keyword: Level Set method

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An Image Segmentation Algorithm using the Shape Space Model (모양공간 모델을 이용한 영상분할 알고리즘)

  • 김대희;안충현;호요성
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.2
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    • pp.41-50
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    • 2004
  • Since the MPEG-4 visual standard enables content-based functionalities, it is necessary to extract video objects from video sequences. Segmentation algorithms can largely be classified into two different categories: automatic segmentation and user-assisted segmentation. In this paper, we propose a new user-assisted image segmentation method based on the active contour. If we define a shape space as a set of all possible variations from the initial curve and we assume that the shape space is linear, it can be decomposed into the column space and the left null space of the shape matrix. In the proposed method, the shape space vector in the column space describes changes from the initial curve to the imaginary feature curve, and a dynamic graph search algorithm describes the detailed shape of the object in the left null space. Since we employ the shape matrix and the SUSAN operator to outline object boundaries, the proposed algorithm can ignore unwanted feature points generated by low-level image processing operations and is, therefore, applicable to images of complex background. We can also compensate for limitations of the shape matrix with a dynamic graph search algorithm.

A Novel Multi-focus Image Fusion Technique Using Directional Multiresolution Transform (방향성 다해상도 변환을 사용한 새로운 다중초점 이미지 융합 기법)

  • Park, Dae-Chul;Atole, Ronnel R.
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.4
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    • pp.59-68
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    • 2009
  • This paper addresses a hybrid multi-focus image fusion scheme using the recent curvelet transform constructions. Hybridization is obtained by combining the MS fusion rule with a novel "copy" method. The proposed scheme use MS rule to fuse the m most significant terms in spectrum of an image at each decomposition level. The scheme is dubbed in this work as m-term fusion in adherence to its use of the MSC (most significant coefficients) in the transform set at any given scale, orientation, and translation. We applied the edge-sensitive objective quality measure proposed by Xydeas and Petrovic to evaluate the method. Experimental results show that the proposed scheme is a potential alternative to the redundant, shift-invariant Dual-Tree Complex Wavelet transforms. In particular, it was confirmed that a 50% m-term fusion produces outputs with no visible quality degradation.

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Evaluation of the bond strength between aged composite cores and luting agent

  • Polat, Serdar;Cebe, Fatma;Tuncdemir, Aliriza;Ozturk, Caner;Usumez, Aslihan
    • The Journal of Advanced Prosthodontics
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    • v.7 no.2
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    • pp.108-114
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    • 2015
  • PURPOSE. The aim of this study was to evaluate effect of different surface treatment methods on the bond strength between aged composite-resin core and luting agent. MATERIALS AND METHODS. Seventy-five resin composites and also seventy-five zirconia ceramic discs were prepared. 60 composite samples were exposed to thermal aging (10,000 cycles, 5 to $55^{\circ}C$) and different surface treatment. All specimens were separated into 5 groups (n=15): 1) Intact specimens 2) Thermal aging-air polishing 3) Thermal aging- Er:YAG laser irradiation 4) Thermal aging- acid etching 5) Thermal-aging. All specimens were bonded to the zirconia discs with resin cement and fixed to universal testing machine and bond strength testing loaded to failure with a crosshead speed of 0.5 mm/min. The fractured surface was classified as adhesive failure, cohesive failure and adhesive-cohesive failure. The bond strength data was statistically compared by the Kruskal-Wallis method complemented by the Bonferroni correction Mann-Whitney U test. The probability level for statistical significance was set at ${\alpha}$=.05. RESULTS. Thermal aging and different surface treatment methods have significant effect on the bond strength between composite-resin cores and luting-agent (P<.05). The mean baseline bond strength values ranged between $7.07{\pm}2.11$ and $26.05{\pm}6.53$ N. The highest bond strength of $26.05{\pm}6.53$ N was obtained with Group 3. Group 5 showed the lowest value of bond strength. CONCLUSION. Appropriate surface treatment method should be applied to aged composite resin cores or aged-composites restorations should be replaced for the optimal bond strength and the clinical success.

The Effect of Aqua Exercise on Female Patients with Knee Degenerative Arthritis (수중운동이 무릎퇴행성관절염 여성 환자에 미치는 영향)

  • Park, Jin-Sik;Yoo, Wang-Keun;Jung, Hyun-Suk;Han, Jong-Man;Yang, Kyung-Han
    • Journal of Society of Preventive Korean Medicine
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    • v.12 no.3
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    • pp.129-139
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    • 2008
  • The purpose of this study was to investigate the effect of aqua exercise on women 50 years of age or older with knee degenerative arthritis, and then examining the therapeutic value of aqua exercise in degenerative arthritis of the knee. The subjects of the study were 115 residents 50 years of age or older who had been diagnosed as degenerative arthritis of the knee by doctors from medical institutions and applied for the aqua exercise program in the Public Health Care Center in Suseong-gu in 2006 and 2007. Experiments were conducted to all the subjects with the application of the 8-week aqua exercise program (2 times a week, 50 minutes a time), designed in the study, and the differences before and after the aqua exercise were compared through questionnaires for measuring the state of the body such as the knee extension angles, weight, body fat, and abdominal obesity. The data was analyzed by t-test and the Wilcoxon method through SPSS 14.0 and the statistical significance level ${\alpha}$ was set at 0.05 and 0.01. The results of the study are as the following. First, In comparison of before and after the aqua exercise, there was improvement in the extension angle of the right knee(p<0.01), while there was some improvement in the extension angle of the left knee, it was not significant. Second, In comparison of before and after the aqua exercise there were statistically significant differences in weight(p<0.05), body fat ratio, and abdominal obesity(p<0.01). The results of this study showed that the aqua exercise program to female patients with knee degenerative arthritis significantly increased the extension angle of the knee. Therefore it is thought that aqua exercise is an effective meditating method to improve their symptoms of female patients 50 years of age or older

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The Actual Wearing Condition for the Uniform of Pediatric Inpatient (소아환자복의 착의실태에 관한 연구)

  • Kim, Mi Sung;Lee, Jeong Ran
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.11
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    • pp.1197-1207
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    • 2012
  • This study provides information for the design of pediatric inpatient uniforms with functionality and aesthetic beauty through a questionnaire-survey of the conditions of providing, wearing, preferences and improvement requirements for pediatric inpatient uniforms. As a result of the survey, intravenous injections were mostly given on the back of the hand, and the method of changing uniforms after intravenous injections was (in most cases) to pass the injection bottle through a sleeve or pant leg while the needle is inserted. The respondents answered that the sleeve length and pant length did not match. As a result of the preference of the pediatric inpatient design survey, respondents indicated they preferred pajama type, yellow color and medium size animal patterns. A similar ratio of set-in and raglan with no collar but with 3/4 length sleeve of round neck, front end, sleeve top opening, button closing and two pockets were preferred for shirts; however, a 3/4 length with rubber string on the waist, no opening and inner opening were preferred at the same ratio for pants. As for the method to adjust the length to assign functionality to pediatric inpatient uniforms, the most preferred sleeve was a roll-up sleeve with a strap and the most preferred pants were length adjusted pants that used a strap for both shirts and pants with a both sides strap. In addition, the majority of the respondents answered that a hand wrapper that protects the injection location during intravenous injections needs be developed. As for the development type, a half glove type and glove type were preferred in sequential order.

Effect of Kinetic Degrees of Freedom on Hierarchical Organization of Multi-element Synergies during Force Production and Releasing Tasks

  • Kim, Kitae;Song, Junkyung;Park, Jaebum
    • Korean Journal of Applied Biomechanics
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    • v.30 no.2
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    • pp.131-144
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    • 2020
  • Objective: The purpose of this study was to examine the effect of degrees of freedom on the multi-synergies in two hierarchies of human hand system during force production and releasing tasks. Method: In this study, the constrained movements of the aiming and releasing actions using both hands and fingers during archery-like shooting were implemented as experimental tasks. The participants produced a pulling force holding the customized frame (mimicking an archery bow, with a set of force transducers) and kept it consistently for about 5 seconds, and released fingers as quickly as possible in a self-paced manner within the next 5 seconds. An analytical method based on the uncontrolled manifold hypothesis was used to quantify the stability index (synergy index) in two hierarchies including two hands (upper hierarchy) and individual fingers (lower hierarchy). Results: The results confirmed that the positive synergy pattern showed simultaneously at the upper and lower hierarchies, and the kinetic degrees of freedom were associated with the increment of hierarchical synergy indices and the performance indices. Also, the synergy indices of both hierarchies showed significant positive correlations with the performance accuracy during the task. Conclusion: The results of this study suggest that the human control system actively uses extra degrees of freedom to stabilize task performance variables. Further increasing the degree of freedom at one level of hierarchy induces positive interactions across hierarchical control levels, which in turn positively affects the accuracy and precision of task performance.

Evaluation of Eye Irritation Potential of Solid Substance with New 3D Reconstructed Human Cornea Model, MCTT HCETM

  • Jang, Won-hee;Jung, Kyoung-mi;Yang, Hye-ri;Lee, Miri;Jung, Haeng-Sun;Lee, Su-Hyon;Park, Miyoung;Lim, Kyung-Min
    • Biomolecules & Therapeutics
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    • v.23 no.4
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    • pp.379-385
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    • 2015
  • The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCE$^{TM}$ which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCE$^{TM}$ can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines.

Improved Method of Suitability Classification for Sesame (Sesamum indicum L.) Cultivation in Paddy Field Soils

  • Chun, Hyen Chung;Jung, Ki Yuol;Choi, Young Dae;Lee, Sanghun
    • Korean Journal of Soil Science and Fertilizer
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    • v.50 no.6
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    • pp.520-529
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    • 2017
  • In Korea, the largest agricultural lands are paddy fields which have poor infiltration and drainage properties. Recently, Korean government pursuits cultivating upland crops in paddy fields to reduce overproduced rice in Korea. In order to succeed this policy, it is critical to set criteria suitability classification for upland crops cultivating in paddy field soils. The objective of this study was developing guideline of suitability classification for sesame cultivation in paddy field soils. Yields of sesame cultivated in paddy field soils and soil properties were investigated at 40 locations at nationwide scale. Soil properties such as topography, soil texture, soil moisture contents, slope, and drainage level were investigated. The guideline of suitability classification for sesame was determined by multi-regression method. As a result, sesame yields had the greatest correlation with topography, soil moisture content, and slope. Since sesame is sensitive to excessive soil moisture content, paddy fields with well drained, slope of 7-15% and mountain foot or hill were best suit for cultivating sesame. Sesame yields were greater with less soil moisture contents. Based on these results, area of best suitable paddy field land for sesame was 161,400 ha, suitable land was 62,600 ha, possible land was 331,600 ha, and low productive land was 1,075,500 ha. Compared to existing suitability classification, the new guideline of classification recommended smaller area of best or suitable areas to cultivate sesame. This result may suggest that sesame cultivation in paddy field can be very susceptible to soil moisture contents.

EMF Measurement and Safety Assessment Method for Wireless Power Transfer System for Urban Railroad (도시철도용 무선 급집전 시스템 주변의 전자기장 측정 방법 및 안전성 평가 방법 연구)

  • Gimm, Yoon-Myoung;Kim, Jun-Hee;Ju, Young-Jun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.12
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    • pp.942-952
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    • 2018
  • A wireless power transfer (WPT) system for an urban railroad is currently under development in S. Korea. This system supplies power to railroad cars using 60 kHz magnetic fields. The electromagnetic fields (EMFs) generated by the WPT system should satisfy established safety requirements for exposure of the human body to these fields. However, EMF measurements and the safety assessment methods for fields generated by the WPT system have not yet been established. As such, a measurement and safety assessment method for EMF generated by a WPT system for an urban railroad is proposed in this report. The EMF generated by this WPT system on a test railroad was measured and compared to the reference level set by the human safety standard for EMF exposure.

Flipped Learning: Strategies and Technologies in Higher Education

  • Miziuk, Viktoriia;Berdo, Rimma;Derkach, Larysa;Kanibolotska, Olha;Stadnii, Alla
    • International Journal of Computer Science & Network Security
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    • v.21 no.7
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    • pp.63-69
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    • 2021
  • Flipped learning is necessary for modern education but quite difficult to implement. In pedagogical science, the question remains to what extent the practical work of the teacher in combination with the technologies of flipped learning will improve the quality of higher education. The aim of this article is to study the effectiveness and feasibility of using flipped learning technologies, assessing their perception by students (advantages and problems), identified an algorithm for introducing flipped learning technology in higher education institutions. Research methods. The main method is an experiment. An evaluation of the effectiveness of the study was conducted using a questionnaire and observation method. Statistical methods were used to evaluate the results of the experiment. The research hypothesis is that flipped learning allows the teacher to spend more time on an individual approach, to understand the real needs of students, and provide effective feedback, thereby improving the quality of learning and motivation of students, especially while studying complex material. The results of the study are to prove the effectiveness of the technology of flipped education in the study of complex disciplines, courses, topics. The use of flipped learning strategies improves the self-regulation of the educational process, group work skills, improves students' ability to learn, overcome difficulties. The technology of flipped learning in the presence of modern technical means and constant work on improving the level of digital literacy is an effective means for students to master complex topics and problematic issues that require additional consideration and discussion. The perspective of further research is the consideration of integrated approaches to the application of flipped learning technologies to the principles of STEAM-education, multilingual and multicultural programs, etc. It is also worth continuing to develop a set of methods aimed at enhancing the student's learning activities, the formation of group work skills, direct participation in creating the foundations of higher education.