• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.839-846
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• 2016

Bin picking is a task of picking a small object from a bin. For accurate bin picking, the 3D pose information, position, and orientation of a small object is required because the object is mixed with other objects of the same type in the bin. Using this 3D pose information, a robotic gripper can pick an object using exact distance and orientation measurements. In this paper, we propose a 3D vision technique for accurate measurement of 3D position and orientation of small objects, on which a paper label is stuck to the surface. We use a maximally stable extremal regions (MSERs) algorithm to detect the label areas in a left bin image acquired from a stereo camera. In each label area, image features are detected and their correlation with a right image is determined by a stereo vision technique. Then, the 3D position and orientation of the objects are measured accurately using a transformation from the camera coordinate system to the new label coordinate system. For stable measurement during a bin picking task, the pose information is filtered by averaging at fixed time intervals. Our experimental results indicate that the proposed technique yields pose accuracy between 0.4~0.5mm in positional measurements and $0.2-0.6^{\circ}$ in angle measurements.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.151-157
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• 2004

Purpose : To evaluate the quantitative accuracy of three-dimensional (3D) images by means of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. Materials and Mathods : An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0/sup TM/(Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. Results: 11 line items in Conventional 3 mm, 8 in Helical 3mm, 11 in Conventional 5mm, 10 in Helical 5mm, 5 in Conventional 7mm and 9 in Helical 7mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2mm in 19 line items of Conventional 3mm, 20 of Helical 3mm, 15 of Conventional 5mm, 18 of Helical 5mm, II of Conventional 7mm and 16 of Helical 7mm. Conclusion: Considering image quality and patient's exposure time, scanning protocol of Helical 5mm is recommended for 3D image analysis of the skull in CT.

• The korean journal of orthodontics
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• v.53 no.2
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• pp.77-88
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• 2023

Objective: To develop a method for generating three-dimensional (3D) digital models of the periodontal ligament (PDL) using 3D cone-beam computed tomography (CBCT) reconstruction and to evaluate the accuracy and agreement of the 3D PDL models in the measurement of periodontal bone loss. Methods: CBCT data collected from four patients with skeletal Class III malocclusion prior to periodontal surgery were reconstructed at three voxel sizes (0.2 mm, 0.25 mm, and 0.3 mm), and 3D tooth and alveolar bone models were generated to obtain digital PDL models for the maxillary and mandibular anterior teeth. Linear measurements of the alveolar bone crest obtained during periodontal surgery were compared with the digital measurements for assessment of the accuracy of the digital models. The agreement and reliability of the digital PDL models were analyzed using intra- and interexaminer correlation coefficients and Bland-Altman plots. Results: Digital models of the maxillary and mandibular anterior teeth, PDL, and alveolar bone of the four patients were successfully established. Relative to the intraoperative measurements, linear measurements obtained from the 3D digital models were accurate, and there were no significant differences among different voxel sizes at different sites. High diagnostic coincidence rates were found for the maxillary anterior teeth. The digital models showed high intra- and interexaminer agreement. Conclusions: Digital PDL models generated by 3D CBCT reconstruction can provide accurate and useful information regarding the alveolar crest morphology and facilitate reproducible measurements. This could assist clinicians in the evaluation of periodontal prognosis and establishment of an appropriate orthodontic treatment plan.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.4
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• pp.337-345
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• 2011

Purpose: The purpose of this study was to define the relation of the degree of menton deviation and 3-D CT (computerized tomography) measurements of the glenoid fossa and the mandible, which are considered to have an influence on menton deviation. Methods: The CT images were obtained in 60 adults and these were transmitted to a computer and reconstructed using computer software. According to the degree of the menton deviation, which was measured on the posteroanterior cephalogram, the subjects were divided into the menton deviated group (30 adults) and the symmetry group (30 adults). A total of 11 measurements that might have an effect on menton deviation were determined and these were measured in the right and left sides using the function of 3-D measurement in the computer program. The 11 measurements consist of 6 measurements in the glenoid fossa (vertical position of the glenoid fossa and articular eminence, the sagittal position of the glenoid fossa and articular eminence, the depth of the glenoid fossa, and the anterior angle of the glenoid fossa), and 5 measurements in the mandible (ramus length, frontal ramal inclination, lateral ramal inclination, body length, body height). Results: The comparison of the differences between the menton deviated and symmetry groups and correlation analysis on the degree of menton deviation were carried out. The results of comparison of the right and the left difference between the menton deviated and symmetry groups showed that the vertical position and depth of the glenoid fossa were significantly increased in the menton deviated group. Conclusion: The results of the present study show that consideration of the shape and position of the glenoid fossa is necessary for making the diagnosis and administering proper treatment in facial asymmetry patients and especially growing patients.

• Speech Sciences
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• v.8 no.3
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• pp.235-241
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• 2001

The purpose of this study was to determine the correlation between HNR and NNE, EGG HNR and EGG NNE, which are most closely related to noise of voice. Dr. Speech was utilized to obtain acoustic measurements and physiologic measurements, simultaneously. In addition, no normative data of HNR, NNE, EGG HNR, EGG NNE are available in Korean subjects at present. The Pearson correlation coefficient was used to find the correlation between HNR and NNE, EGG HNR and EGG NNE. The results of the study were as follows: First, there was no correlation between HNR and NNE. Second, there was a negative correlation between EGG HNR and EGG NNE. Finally, the mean value of HNR of normal Korean adults was $28.8\pm2.7$ dB, that of NNE -$11.7\pm3.9$ dB, that of EGG HNR $32.9\pm4.6$ dB, and that of EGG NNE $-30.3\pm4.6$ dB.

• Journal of the Korean Mathematical Society
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• v.58 no.1
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• pp.1-28
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• 2021

We study a continuous data assimilation algorithm for the three-dimensional simplified Bardina model utilizing measurements of only two components of the velocity field. Under suitable conditions on the relaxation (nudging) parameter and the spatial mesh resolution, we obtain an asymptotic in time estimate of the difference between the approximating solution and the unknown reference solution corresponding to the measurements, in an appropriate norm, which shows exponential convergence up to zero.

• Journal of Fashion Business
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• v.17 no.3
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• pp.74-84
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• 2013

The purpose of this research is to provide useable data for application in American and Korean apparel company. This data was developed by analyzing information of Korean and American body sizes obtained from "Size USA Project" and "Size Korea Project". The Subjects were 6,306 American females and 1,988 Korean females over 18 years old. 30 measurements and 14 computed values were chosen that were considered critical in making garments. And descriptive analysis, percentile analysis and t-test were used as statistical methods for analyzing measurements and computed value between the two countries. The results were as follows. It was determined that American women were larger and bigger than Korean women in all measurements and computed values, except for Shoulder Slope. Based on BMI values, we determined that American women had a distinct tendency towards being overweight. Through the comparison of drop values (i.e. the difference between Hip and Bust Girths or Hip and Waist Girths), ratio values (i.e. waist height divided by height) and Body Mass Index (BMI) between the two countries, we determined that American women's figures were shapelier than Korean women's. American women had higher hip heights and longer leg lengths for their height compared to Korean woman. Furthermore, the back shapes of Korean women were flatter than American women and BMI values indicated American women were relatively more overweight than Korean women.

• Journal of Ocean Engineering and Technology
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• v.26 no.3
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• pp.61-65
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• 2012

Air-water flow measurements are of importance for the coastal and ocean engineering fields. Although kinematic investigations of the multi-phase flows have been conducted for long time, velocity measurements still are concerned with many researchers and engineers in coastal and ocean areas. In the present study, an imaging technique using shadowgraphy and fiber optic probe for velocity measurements of air bubbles is introduced. The shadow graphy image technique is modified from the typical image velocimetry methods, and optical fibers are used for the well-known intrusive coupled phase-detection probe system. Since the imaging technique is a non-intrusive optical method from the air, it is usually applied for 2D flows. On the other hand, the double fiber optic probes touch flows regardless of flow patterns. The results of the flow measurements by both methods are compared and discussed. The methods are also applied to the measurements of overtopping flows by a breaking wave over the structure fixed on the free surface.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.6
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• pp.988-1001
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• 2018

The head and face are the most complicated structures of the human body. However, unlike apparel products, many of the head and face related products are produced in unisex or one-size-fits-all. Therefore, it is necessary to provide a practical analysis that reflects these size structures. This study analyzed head and face measurements of men, women, and both men and women; its purpose lying in clarifying the differences and commonalities between the measurements of men and women and discovering the possibility of integrating analysis on measurements of men and women. 3D face and head measurement data of men and women from 20 to 29 years-old from Size Korea's 6th human body size data were analyzed for this study. The mutual 9 factors were extracted as the results of the three factor analyses (both men and women) separately and men and women integrated. However in the cluster analysis based on the 9 factors, men and women showed mutual characteristics and different landscape in group types and distribution. The commonalities and differences between men and women observed in this study should be applied to the sizes of head and face products.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.441-448
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• 1994

Postweaning performance data were obtained on 187 group fed purebred Angus calves from 12 selected sires (six high and six low feed conversion sires) in 1985 and 1986. The objective of this portion of the study was to develop prediction equations for feed conversion from a stepwise regression analysis. Variables measured were on-test weight (ONTSTWT), on-test age (ONTSTAG), five weights by 28-d periods, seven linear body measurements: heart girth (HG), hip height (HH), head width (HDW), head length (HDL), muzzle circumference (MC), length between hooks and pins (HOPIN) and length between shoulder and hooks (SHHO), and backfat thickness (BF). Stepwise regressions for maintenance adjusted feed conversion (ADJFC) and unadjusted feed conversion (UNADFC) over the first 140 d of the test, and total feed conversion (FC) until progeny reached 8.89 mm of back fat were obtained separately by conversion groups and sexes and for combined feed conversion groups and sexes. In general, weights were more important than linear body measurements in prediction of feed utilization. To some extent this was expected as weight is related directly to gain which is a component of feed conversion. Weight at 112 d was the most important variable in prediction of feed conversion when data from both feed conversion groups and sexes were combined. Weights at 84 and 140 d were important variables in prediction of UNADFC and FC, respectively, of bulls. ONTSTWT and weight at 140 d had the highest standardized partial regression coefficients for UNADFC and ADJFC, respectively, of heifers. Results indicated that linear measurements, such as MC, HDL and HOPIN, are useful in prediction of feed conversion when feed in takes are unavailable.