• The korean journal of orthodontics
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• v.40 no.2
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• pp.77-86
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• 2010

Objective: The purposes of this study were to evaluate the reproducibility and reliability of head posture obtained by registering outer canthus as a soft tissue landmark with the Outer Canthus Indicator (OCI). Methods: Twenty-one adults with normal facial morphology were enrolled in this study (mean age $27.5\;{\pm}\;1.72$ years). To register initial head posture, height of the outer canthus from the ear rod plane was measured using OCI. Head posture was reproduced by moving the head upwards and downwards until the outer canthus was in a straight line with the indicator set at a registered height. After the head posture is reproduced by two operators after two days, lateral photographs were taken. Computerized photometric analyses of the photographs were performed. Results: The head rotations around the transverse axis were $0.69\;{\pm}\;0.43^{\circ}$, $0.98\;{\pm}\;0.65^{\circ}$ from each of the two operators. Standard errors were $0.09^{\circ}$ and $0.14^{\circ}$ each, which were similar to results from past research findings. There were no significant differences between the data from the two operators (p > 0.05). There were no correlations between the head rotation around the horizontal and vertical axes (p > 0.05). Conclusions: The present study suggests that OCI-registered head posture may minimize errors from vertical head rotation in cephalometry and photometry.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.617-623
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• 2012

This study was performed to measure the accuracy of different gypsum materials by a white light dental scanner. A master model with the prepared lower full arch tooth was used. The type IV and scannable stone were used for 20 stone casts (10 casts each) duplicated a master model of mandible. The distance between the reference points were measured and analyzed by the Delcam $Copycad^{(R)}$ (Delcam Plc, UK) 3D graphic software. The t-student test for paired samples were used for statistical analysis. The mean differences to master model for type IV stone and scannable stone model were 0.29~0.56 mm, and 0.17~0.35 mm, respectively. There were statistical differences in dimensional accuracy for full arch impression between the master model and type IV/scannable stone (p<0.05). Two different gypsum materials showed clinically acceptable accuracies of full arch digital impression produced by them. Besides, in both gypsum materials, the differences to the master model detected appear to provide enough accuracy for clinical application.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.491-501
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• 1999

Precise and accurate measuring of tooth size is essential procedure in orthodontic diagnosis. The purpose of this study was to evaluate the reproducibility and accuracy of tooth size measurements with regard to tooth and investigator. Five investigators measured the size of one side of teeth, from central incisor to first molar, on 20 sets of casts that show a moderate degree of crowding. Mesio-distal width was measured with digital vernier calipers in each tooth and this procedure was repeated three times at two weeks interval. To obtain a standard measurement for each tooth, dental casts were cut into individual tooth, and its width was measured with micrometer. The difference between the measurement from dental cast and the standard measurement was defined as the measurement error. Through various statistical analyses, following results were obtained. 1. The reproducibility did not show significant differences with regard to tooth or investigator. 2. The measurement error showed some difference with regard to tooth and investigator. 3. The magnitude of the measurement error showed increasing tendency from anterior to posterior teeth with maximum value in the first molar. 4. While the measurements obtained on study casts generally showed smaller number compared to standard measurements, the direction of the difference showed variability according to tooth or investigator. 5. The measurement errors did not show significant correlations with the degree of crowding. The results of the present study indicate that the possibility of tooth size measurement error should be taken into consideration when diagnosing an orthodontic case.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.135-142
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• 2013

With a rapid growth of hardware and product material industries, evolution of handheld terminal technologies is progressed. Various applications using mobile phone are the major trend in recent smart applications. Especially, interesting applications using camera module in a smartphone are developed continuously, mobile users are able to use various useful mobile applications nowadays. In this paper, we design and implement smartphone app for measuring real size of the shooting object in the image taken by a camera module in a smartphone precisely. We implement 4 different shooting modes for precise measurement of objects and 0 point control module is developed to minimize the differences of shooting images taken by different types and systems of various smartphones. The smartphone app proposed and implemented in this paper is analyzed and evaluated by a simulation study.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.696-706
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• 2003

The purpose of this study was to clarify the palatal forms through palatal curvatures of right to left, anterior to posterior direction, and difference of right and left palatal volumes in the primary and permanent dentition. Samples were consisted of normal occlusion of both dentition(50 males and 50 females each). Their upper plaster casts were used, measuring points were decided, through 3-dimensional laser scanning(3-D Laser Scanner, DS4060, LDI, U.S.A.), and fitting standard horizontal plane were made for measuring the height and sectioned volumes of palate. The results were as follows: 1. Palatal volume and height were greater at the right side of the palate in the primary and permanent dentition of male and female, but there was no significance. 2. Palatal height was greater in male compared to female, especially, there was significant difference at intercuspid, inter-second premolar area in the permanent dentition(P<0.05). 3. To the height of A-P direction of mid-palatal area, the highest point was 20mm in the primary dentition, 30mm in the permanent dentition from interdental papilla of central incisors. 4. Palatal height of inter-cuspid and inter-second premolar became shallow and broad, high and broad each, compared to inter-deciduous canine and inter-second deciduous molar.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.126-133
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• 2014

The main source of bridge destruction is due to scour. The bridge scour is the result of erosive action of flowing water taking away ground materials from near the abutment or pier. Furthermore, the water level must be also monitored whiling flooding, because it dangers not only the stability of bridge itself, but the safety of bridge users. This study is intended to develop a new measuring system for bridge scour by overcoming the current limitation of scour measurement technique. This measuring system is confirmed its excellence and validity through this study. The newly developed measuring system finds the distance between the water surface and the ground surface by detecting temperature difference along the abutment vertically. The measuring mechanism for monitoring the bridge scour and water level is based on identifying the temperature difference among mediums, including air, water and ground. In order to validate the new measuring system, the lab experiments and the field tests are conducted and compared. It has been confirmed that this system can effectively measure the bridge scour and the water level by analyzing the temperature distribution between mediums and the temperature variation over time.

• Spatial Information Research
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• v.16 no.3
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• pp.279-290
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• 2008

Landslide, one of the serious natural disasters, has Incurred a large loss of human and material resources. Recently, many forecasting or alarm systems based on various kinds of measuring equipment have been developed to reduce the damage of landslide. However, only a few of these equipments are guaranteed to evaluate the safety of whole side of land slope with their accessibility to the slope. In this study, we performed some experiments to evaluate the applicability of a terrestrial LiDAR as a surveying tool to measure the displacement of a land slope surface far a slope collapsing protection system. In the experiments, we had applied a slope stability method to a land slope and then forced to this slope with a load increasing step by step. In each step, we measured the slope surface with both a total station and a terrestrial LiDAR simultaneously. As the result of Slope Fracturing analysis using all targets, the LiDAR system showed that three was 1cm RMSE on X-axis, irregularity errors on Y-axis and few errors on Z-axis compare with Total Station. As the result of Slope Fracturing analysis using continuous targets, the pattern of Slope Fracturing was different according to the location of continuous targets and we could detect a continuous change which couldn't be found using Total station. The accuracy of the LiDAR data was evaluated to be comparable to that of the total station data. We found that a LiDAR system was appropriate to measuring the behaviour of land slope. The LiDAR data can cover the whole surface of the land slope, whereas the total station data are available on a small number of targets. Moreover, we extracted more detail information about the behavior of land slope such as the volume and profile changes using the LiDAR data.

• Korean Journal of Social Welfare
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• v.38
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• pp.7-32
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• 1999

Providing the income support program for people under the poverty level has been regarded as the basic obligational role of modern government. The target population of this program should include all the poor who are unable to maintain the minimum health and decency level with their own income. The minimum living cost, however, varies within a country because there are regional differences in consumer price and the mode of living. The current program does not count for the regional differences, leaving a significant portion of Seoul's poor needy people being ineligible for this public care. Recognizing these regional differences, this paper attempts to estimate the minimum living cost in Seoul area, comparing it to the national one. It employs the data and method that the Korea Institute of Health and Social Affairs adopted in its 1994 study, since it has been served as a basis of the current public assistance program. The minimum cost of living in Seoul is estimated to be \887,611 per month for a 4-person household. It is 1.33 times greater than the national monthly minimum of \666,684. Based upon the '94 urban household expenditure survey data, some 5.9 percent of Seoul's population, 636,132 people, are found to be under the Seoul's minimum living level. This number is 5.2 times greater than those 123,304 people who are eligible for the current public assistance program in Seoul.

• Journal of the Korean Geosynthetics Society
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• v.22 no.1
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• pp.87-96
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• 2023

There are a lot of difference between the surface settlement and the differential settlement measured at the Busan New Port, where the dredged and reclaimed clay layer exists and below the clay is originally thickly distributed. To find the cause and solution of this, the actual conditions of each differential settlement used for the soft ground improvement, characteristics, installation method, measurement frequency, measurement data management, and data analysis of each type were considered. In the deep soft ground improvement work where large deformation occurs, the bending deformation of the screw-type differential settlement gauge is less than that of other types of measuring instruments, so there is less risk of loss, and the reliability of data is relatively high as the instruments are installed by drilling for each stratum. Since the greater the amount of high-precision settlement measurement data, the higher the settlement analysis precision. It is necessary to manage with higher criteria than the measurement frequency suggested in the standard specification. For the data management of the differential settlement gauge, it is desirable to create graphs of the settlement and embankment height of the relevant section over time, such as surface, differential, and settlement of pore water pressure gauge for each point. In the case of multi-layered ground with different compression characteristics, it is more appropriate to perform settlement analysis by calculating the consolidation characteristics of each stratum using a differential settlement data.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.15-22
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• 2005

The Purpose of this study was to clarity morphological differences among mandibular dental arch forms in Korean malocclusion patients. The sample in this study consisted of 114 Class I. 119 Class II, and 135 Class III malocclusion cases. The most facial portions of 13 proximal contact areas were digitized from photocopied images of the mandibular dental arches. Clinical bracket points were calculated for each tooth based on the data on the mandibular tooth thickness. Four linear and two proportional measurements were undertaken The dental arches were classified into square. ovoid, and tapered forms to compare the frequency distributions. Our results suggested that there was no single arch form specific to any particular Angle classification or sex. It appeared to be the frequency of a particular arch form that varies among the Angle classifications. In comparison of arch measurements between male and female. there was no statistical difference except in the intermolar width. In comparison of arch size measurements among the different Angle classifications, there were statistically significant differences between Class I and Class III malocclusion groups and between Class II and Class III malocclusion groups. In comparison oi frequency distribution of arch forms in Class I and III malocclusion groups, the square form demonstrated the highest distribution followed by the ovoid and tapered forms in that order. In the Class II malocclusion group, the square form showed the highest distribution. followed by the tapered and ovoid forms in that order There was no statistical difference in the frequency distribution of arch forms between male and female groups.