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A QUANTITATIVE STUDY OF BONE DENSITY ON RADIOGRAM BY USING IMAGE ANALYZER (영상 분석장치를 이용한 골 흑화도의 정량적 평가에 관한 연구)

  • Choi Won-Jae;Kim Jae-Duk
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.25 no.2
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    • pp.521-533
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    • 1995
  • This study was performed to develop and evaluate the method to detect Quantitatively the serial changes in the size of artificial lesion in the spongious bone by automatic color image analyzer. 15 intraoral radiograms taken before and after endodontic treatment of 5 cases were used for contour line analysis. 30 intraoral radiograms taken by geometrically standardized apparatus before and after serially the formation of artificial lesions of 0.80, 1.20, 1.75, 2.00mm in diameter at the periapical area and interdental area of spongious bone were used. The analysis of image according to the variance of lesion size by 0.25, 0.35, 0.55, and 0.85mm serially was performed by the histogram and the color enhancement with subtraction. The images inputted by CCDcamera were digitized and analyzed by NEXUS QUBE program with NEC PC-9801 computer. The obtained results were as follows: 1. There was no reliability in the analysis of lesions by contour line 2 .. The mean difference of the grey scale at each pixel was 1 step between reference image and the corrected images. 3. In the analysis by histogram of the artificial lesion in spongeous bone, the change over 0.55mm in the mesiodistal size was detectable by the change of the numbers of pixel showing the change in grey scale. 4. In the analysis by histogram of the artificial lesion in spongeous bone, the change over 0.25mm in the buccolingual size was detectable by the change in grey scale. 5. By color enbancement with- subtraction, each lesion was able to be isolated and the change in it's mesiodistal size was detectable visually , but not in it's buccolingual size.

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Linear accuracy of cone-beam computed tomography and a 3-dimensional facial scanning system: An anthropomorphic phantom study

  • Oh, Song Hee;Kang, Ju Hee;Seo, Yu-Kyeong;Lee, Sae Rom;Choi, Hwa-Young;Choi, Yong-Suk;Hwang, Eui-Hwan
    • Imaging Science in Dentistry
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    • v.48 no.2
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    • pp.111-119
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    • 2018
  • Purpose: This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. Materials and Methods: CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. Results: Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements(P<.05). The quality of the CBCT surface volume-rendered images acquired at a constant threshold varied across different exposure conditions. Conclusion: These results proved that existing 3D imaging techniques were satisfactorily accurate for clinical applications, and that optimizing the variables that affected image quality, such as the exposure parameters, was critical for image acquisition.

Comparison of two computerized occlusal analysis systems for indicating occlusal contacts

  • Jeong, Min-Young;Lim, Young-Jun;Kim, Myung-Joo;Kwon, Ho-Beom
    • The Journal of Advanced Prosthodontics
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    • v.12 no.2
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    • pp.49-54
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    • 2020
  • PURPOSE. The purpose of this study was to compare the performance of Accura to that of the T-scan for indicating occlusal contacts. MATERIALS AND METHODS. Twenty-four subjects were selected. Their maxillary dental casts were scanned with a model scanner. The Stereolithography files of the casts were positioned to align with the occlusal plane. Occlusal surfaces of every tooth were divided into three to six anatomic regions. T-scan and Accura recordings were made during two masticatory cycles. The T-scan and Accura images were captured at the maximum bite force and overlapped to the cast. Photographs of interocclusal records were used as the reference during overlap. The occlusal contacts were counted to compare the T-scan and Accura. McNemar's test was used for statistical significance and the corresponding P-values were calculated from a chi-square distribution with one degree of freedom. The accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Accura were calculated relative to the T-scan values as a control. RESULTS. No statistical differences (P>.05) were found between the T-scan and Accura methods. The accuracy of Accura was 75.8%, sensitivity was 82.1%, specificity was 60.1%, PPV was 82.9%, and NPV was 60.1%. CONCLUSION. Accura could be another possible option as a computerized occlusal analysis system for indicating occlusal contacts at maximum intercuspation.

Estimation of Dynamic Characteristics of Core Zone of Rockfill Dam by Multi-channel Analysis of Surface Waves (MASW 조사를 통한 사력댐 코어존 동적물성의 평가)

  • Lee, Jong-Wook;Ha, Ik-Soo;Oh, Byung-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.860-868
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    • 2008
  • Seismic safety analysis of rockfill dams are consist of the stability analysis as an simplifed method and the dynamic analysis as an detailed method. When high risk dams such as Multi-purpose dams were often applied detailed method by dynamic analysis, dynamic properties of dam materials such as shear modulus are considered as most important factor. Dynamic material properties such as shear modulus had to be investigated by cyclic triaxial test et al. during design and construction stage but these were not conducted because of the condition of domestic seismic design technique. MASW and SASW methods had been applied as a non destructive method to investigate dynamic material properties of existing rockfill dam, has no problems in dam safety at present. These methods were usually performed under the assumptions that the subsurface can be described horizontally homogeneous and isotropic layers. Recent studies(Marwin, 1993, Kim, 2001) showed that surface waves generated through inclined structures have different characteristics from those through a horizontally homogeneous layered model. further Kim et al(2005) and Min and Kim(2006) showed that central core type rockfill dam overestimated the shear wave velocities as increasing the depth through the 3D numerical modelling dut to the effect of outer rockfill and geometrical reasons In this study the results of shear wave velocities of seven rockfill dams form comprehensive facility review, was carried out from 2003 to 2007, were collected and analysed to establish the shear wave velocity distribution characteristics in increasing confining stress in rockfill dams and surface wave velocity ranges in rockfill dam through MASW and the limitation in application are discussed to be utilized as an reference value for dynamic analysis.

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Quantified Comparison of Work Characteristics for Musculoskeletal Hazards Assessment of Industrial Workers (생산직 근로자의 근골격계질환 위험성 평가를 위한 작업특성의 수량화 비교)

  • Lim, Hyeon-Kyo;Yun, Jong-Hun;Luo, Meiling
    • Journal of the Korean Society of Safety
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    • v.27 no.3
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    • pp.131-140
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    • 2012
  • Though there might exist not a few differences between cyclic works and atypical works, many researchers have applied the same assessment techniques that used for repetitive works, which may result introduce bias in their conclusions. This research aimed to verify whether there exist non-negligible work characteristics and/or dissimilarity among works with different work nature and whether one of the most prevalent assessment techniques for assessing ergonomic hazards of musculoskeletal disorders, REBA, can be applied to atypical works. For a general hospital, an automobile repair shop, and two auto-part assembly plants which manufactures quite different parts, a questionnaire survey and field investigation and ergonomic assessment were carried out and analyzed statistically with reference to the 3rd Quantification technique. The results showed that there exist remarkable difference between physical factors in cyclic works and atypical non-cyclic works. As for repetitive work, body posture was significant factors affecting on musculoskeletal disorders while atypical works seemed to have none which implied that the necessity of taking psychosocial factors into account for assessment of hazards. Complain rate in repetitive works was highest shoulder, back, and neck or wrist in sequence. However, there existed no consistent trend in complain rate in atypical works. And, though weight of manufacturing objects was a common factor that can partly explain musculoskeletal complain, time duration was significant in atypical work whereas repeatability and body posture were significant in repetitive works. As being the results, to summarize, it could be said that application of conventional ergonomic assessment techniques regardless of repetitiveness would be fruitless, and that the necessity of a unique methodology focused on atypical non-cyclic works should not be neglected.

A Study on the Characteristics of Daylight Distributions by Different Sky Conditions and Controlled Roller Shade Heights (천공종류 및 롤러쉐이드의 제어된 높이에 따른 주광분포 특성에 관한 연구)

  • Park, Byoung-Chul;Lim, Ji-Sun;Kim, Yu-Sin;Lee, Jeong-Ho;Choi, An-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.2
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    • pp.18-26
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    • 2009
  • Daylight responsive dimming systems are one of lighting control systems which are to control artificial lightings using available daylight for energy savings. This system is not popular because useful daylight is usually blocked by uncontrolled passive shading systems in buildings. It is necessary to integrate daylight responsive dimming systems and automata! roller shading systems. In this research, mock-up test is performed to analyze the daylight distributions in three different rooms for integrated systems. Roller shades are installed in two rooms. One is fully downed and the other is controlled by sun profile angle. The other room has no shading system as a reference room.

Adaptively Compensated-Disparity Prediction Scheme for Stereo Image Compression and Reconstruction (스테레오 영상 압축 및 복원을 위한 적응적 변이보상 예측기법)

  • 배경훈;김은수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7A
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    • pp.676-682
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    • 2002
  • In this paper, an effective stereo image compression and reconstruction technique using a new adaptively compensated-disparity prediction scheme is proposed. That is, by adaptively predicting the mutual correlation between the stereo image using the proposed method, the bandwidth of the stereo input image can be compressed to the level of the conventional 2D image and the predicted image also can be effectively reconstructed using this transmitted reference image and disparity data in the receiver. Especially, in the proposed method, once the feature values are extracted from the input stereo image, then the matching window size for the predicted image reconstruction is adaptively selected in accordance with the magnitude of this feature values. From this adaptive disparity estimation method, reduction of the mismatching probability of the disparity vectors is expected and as a result, the image quality in the reconstructed image can be improved. In addition, from some experiments using the CCETT's stereo images of 'Fichier', 'Manege' and 'Tunnel', it is shown that the proposed method improves the PSNR of the reconstructed image to about 9.08 dB on average by comparing with that of the conventional methods. And also, it is found that there is almost no difference between the original image and the predicted image reconstructed through the proposed method by comparison to that of the conventional methods.

Development of Job Description of Nutrition Teacher by the DACUM Method (DACUM 기법에 의한 영양교사 직무기술서 개발)

  • Kim, Ji-Hee;Cha, Jin-A
    • Journal of the Korean Dietetic Association
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    • v.22 no.3
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    • pp.193-213
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    • 2016
  • The purpose of this study is to provide a standard job description for a nutrition teacher placed in primary and secondary schools by analyzing their duties. DACUM is an acronym for 'Developing A CUrriculuM'. It was used by experts to determine the job duties, tasks and task elements to establish the job descriptions of a nutrition teachers through the development of a DACUM chart. An expert panel consisting of 10 nutrition teachers participated in a DACUM workshop and derived nutrition teacher's DACUM chart. A total of 1,550 nutrition teachers across the country were targeted as the survey subjects for validation of the DACUM chart through their perception of the frequency, importance, and difficulty of each item in the job description. A tree structure, criticality analysis, and contents validity index were added for verification. The definition of the nutrition teacher's job and DACUM chart with 5 duties, 28 tasks, and 107 task elements were derived by the DACUM method. The definition of a nutrition teacher was 'A teacher who is responsible for food service management and nutrition education and counseling for health promotion and disease prevention for students in primary and secondary schools'. The validation results of the tree structure were the priorities of the 28 tasks with ranks 1 and 2. Because there was no third priority, it was considered to be a good representation of the tasks of nutrition teachers. The DACUM chart was found to be evenly distributed with relative importances of more than 17 or less than 11 through the criticality analysis. Since the C5-4 (Conduct simulation exercise against food poisoning)'s content validity index was significantly less than the reference value of 0.78, it was not included in the final job description. 5 duties, 28 tasks, 102 task elements were included in the final job description of a nutrition teacher.

A Study on the Salt Contents in Foods Served by Institutional Foodservice Establishment (산업체 급식에서 제공되는 식사의 염분 함량에 관한 연구)

  • Kim, Hyun-Ah;No, Sung-Yun;Lee, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.5
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    • pp.739-745
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    • 2008
  • This study was conducted to determine the salt-intake from meals that were served by an institutional foodservice establishment for a month. Meals (176) were classified into 12 food groups by CAN Pro 3.0. These consisted of bap 6, mandu 5, guk 29, jjigae 9, jjim 4, gui 8, jeon 5, bokeum 25, jorim 16, fried 7, namul 49, pickled 12. The average salt content of 100 g of each menu item was significantly higher in the order of pickled>jorim>bokeum>gui>namul>jeon>jjigae>jjim>fried. The average salt and sodium contents of 1 potion of menu item was significantly higher in the order of jjigae>mandu>guk>bap>jorim>pickled>bokeum>gui>fried>jjim>gimchi>namul>jeon. The average salt contents of kim-chijjigae (6.05 g), eggjorim (7.01 g), cooked namul (2.78 g) and salted pepperleaves (4.67 g) was higher than that of the other menu items served frequently in the establishment. The average intake of salt and sodium was 23.48 g (sodium 9,310 mg) a day, 7.35 g (sodium 2,960 mg) with breakfast, 7.55 g (sodium 2,990 mg) with lunch and 8.33 g (sodium 3,300 mg) with dinner. The daily salt intake was slightly higher than that of DRIs (Dietary Reference Intakes).

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The Review and Study Trend of Moxibustion - Focusing on Donguibogam(東醫寶鑑) Vol. Acupuncture & Moxibustion(鍼灸篇) - (뜸에 대한 문헌고찰 및 국내 연구동향 분석 - 동의보감(東醫寶鑑) 침구편(鍼灸篇)을 중심으로 -)

  • Chun, Sang-Hee;Wang, Myoung-Ja
    • Journal of East-West Nursing Research
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    • v.8 no.1
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    • pp.135-146
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    • 2003
  • Moxibustion plays an important role not only in the medical service, but also in the health care of Korea. So this study attempted to review of moxibustion and analyze of domestic study trend. And it also intends to examine the usefulness of moxibustion treatment in Korean nursing intervention. "Donguibogam" is famous for the most comprehensive medical book in ancient Korea, indicates that moxibustion makes up a large part of it and that its contents were composed of material, size, time, caring of one's health, indication, operational procedure, contraindication in the documented in the 25 reference books. Also, It confirms that it has been widely used since old times. Especially, it seems to be a great help to researchers because its content lay a theoretical foundation. From the literature, we identified that moxibustion was most widely using method for health promotion and an efficacious cure for a disease. I searched and investigated the journals and dissertations supplied by KERIS and RICH with the key word "moxibustion". Of 10 articles with moxibustion intervention, the trend of domestic studies shows, that of an area relating to nursing was 5. Therefore, moxibustion intervention steadily increases in frequency in nursing academic circles year by year. But there is no distinction between hand moxibustion and moxibustion. According to the above results, we need to develop moxibustion learning program and well designed experimental study with moxibustion for Korean Nursing intervention.

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