• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.35-41
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• 2020

3D laser scanners are an effective way to quickly acquire a large amount of data about an object. Recently, it is used in various fields such as surveying, displacement measurement, 3D data generation of objects, construction of indoor spatial information, and BIM(Building Information Model). In order to utilize the point cloud data acquired through the 3D laser scanner, it is necessary to make the data acquired from many stations through a matching process into one data with a unified coordinate system. However, analytical researches on the accuracy of point cloud data according to the registration method are insufficient. In this study, we tried to analyze the accuracy of registration method of point cloud data acquired through 3D laser scanner. The point cloud data of the study area was acquired by 3D laser scanner, the point cloud data was registered by the ICP(Iterative Closest Point) method and the shape registration method through the data processing, and the accuracy was analyzed by comparing with the total station survey results. As a result of the accuracy evaluation, the ICP and the shape registration method showed 0.002m~0.005m and 0.002m~0.009m difference with the total station performance, respectively, and each registration method showed a deviation of less than 0.01m. Each registration method showed less than 0.01m of variation in the experimental results, which satisfies the 1: 1,000 digital accuracy and it is suggested that the registration of point cloud data using ICP and shape matching can be utilized for constructing spatial information. In the future, matching of point cloud data by shape registration method will contribute to productivity improvement by reducing target installation in the process of building spatial information using 3D laser scanner.

• Korean Journal of Occupational Health Nursing
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• v.15 no.2
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• pp.83-93
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• 2006

Purpose: This study purposed on investigating how the emotional labor affects the physical uncomfortable feeling of the workers in the department store. Method: The method of data collection was used of questionnaire for 574 workers of one department store located in Seoul. The period of data collection was done from November 1, 2004 to November 30 for about one month. The working career of the participants was over one month at that department. Result: The degree of emotional labor for participants, men were $3.21{\pm}0.53$ for the total point of 5.0 point, and the degree of the physical uncomfortable feeling was $3.07{\pm}0.48$ for total of 5.0 point. The degree of emotional labor for participants, women were $3.22{\pm}0.42$ for the total point of 5.0 point, and the degree of the physical uncomfortable feeling was $3.13{\pm}0.42$ for total of 5.0 point. In order to analyze the factors that affected the emotional labor and physical uncomfortable feeling, the multi-level reflecting analysis was used. As a result, men were insecurity of job influenced the emotional labor feeling in remarkable degree, women were the responsibility of job influenced the emotional labor. Men were insecurity and responsibility of job influenced physical uncomfortable feeling in remarkable degree, women were responsibility of job and emotional labor influenced the physical uncomfortable feeling in remarkable degree. Conclusion: The results of this study show that various strategies to remove the factors of job insecurity in order to reduce the level of emotional labor of the workers at the department store should be devised. In addition, the special way to minimize the physical insecurity should be contrived and carried out. Since the workers of the department stores had higher emotional labor, the factors of stress need to be analyzed and should be removed.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.299-303
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• 2011

This paper proposes a novel sensorless maximum power point tracking (11PPT) algorithm for PV systems. The method is based on dividing the operating time into several intervals in which the PV terminals are short circuited in one interval and the calculated short-current of the PV is obtained and used to determine the optimum operating point where the maximum output power can be obtained. The proposed MPPT algorithm has been introduced into a current-controlled boost converter whose duty ratio is controlled to the maintain MPP condition. The same sequence is then repeated regularly capturing the PV maximum power. The main advantage of this method is eliminating the current sensor. Meanwhile, this MPPT algorithm reduces the power oscillations around the peak power point which occurs with perturbation and observation algorithms. In addition, the total cost will decrease by removing the current sensor from the PV side. Finally, simulation results confirm the accuracy of the proposed method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.5
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• pp.84-88
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• 2023

This study proposes an automated tilt measurement method using point cloud for buildings. The proposed method consists of two main steps: 1) exterior wall plane extraction, and 2) edge estimation and angle calculation. To validate the performance of the proposed method, the algorithm is applied to a target building, of which the estimated tilt values are compared with those obtained from a total station, a commonly used tool for tilt measurement. The result shows that most estimated tilt values are within the maximum and minimum ranges of the total station measurement, suggesting that the proposed algorithm provides sufficient measurement accuracy. Furthermore, the proposed method is shown to be automated and reliable as well as free from human-induced errors compared to the total station.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.7-22
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• 1997

A finite element analysis is performed for lateral buckling problems on the basis of a geometrically nonlinear formulation for a beam with small elastic strain but with possibly large rotations. The total Lagrangian formulation for a general large deformation, which involves finite rotations, is chosen and the exponential map is used to treat finite rotations from the Eulerian point of view. For lateral buckling, the point of vanishing determinant of the resulting unsymmetric tangent stiffness is traced to examine its relationship to bifurcation points. It is found that the points of vanishing determinant is not corresponding to bifurcation points for large deformations in general, which suggests that the present unsymmetric tangent stiffness is not an exact first derivative of internal forces with respect to displacement. This is illustrated through several numerical examples and followed by appropriate discussion.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.450-457
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• 2016

The Total Maximum Daily Load (TMDL) is a watershed management system that involves the establishment of the target water quality, the calculation of permission loading (allocation loading), and the control of total pollutants for each unit watershed. Allocation loading is assessed through the comprehensive implementation assessment of the previous year's plan. Assessment results are used for follow-up management measures such as the limit of development and updating of TMDL Management Implementation Plans for the next planning period. Although detailed assessment criteria are important, they are not currently available. Therefore, we suggested assessment criteria by comparing two methods('integration method' and 'separation method') using combination point and non-point discharge loading. We also examined the penalty criteria considering controllable load local government and updating methods of the TMDL Management Implementation Plan for the next planning period.

• Journal of Korean Academy of Nursing
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• v.7 no.2
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• pp.22-30
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• 1977

An analysis of the Nursing activities was carried out during the period of October 6 - 10, 1975 for five days, at postanesthetic room in Seoul National University Hospital. Continuous Time Study method was applied to this study by Observing and checking the activities performed by 8 nursing personnel at head nurse, staff nurse, and nurse aide level. Six nursing Students and 6 staff nurses observed and recorded all activities during the day and the evening for 5 days after certain process of training. Following results were obtained I 1. Percentages of nursing activity os were identified at each level of nursing personnel according to the skill Level 1) Thirty three point forty two Percent of the total head nurse's activities were spent by administrative activities, 21,33% by Clerical activities, 10.63% by Nursing activities, 6.54% by Messenger activities, 4.0% by Housekeeping activities, and 24. 08% by Unclassified activities, 2) Forty point forty two percent of the total staff nurses'activities were spent by Nursing activities, 12.7% by Administrative activities, 8.03% by Housekeeping activities, 3.08% by Clerical activities, 2.03% by Messenger activities, 0.08% by Dietary activities, and 34.19 o/e by Unclassified activities. 3) Thirty six point sixty three percent of the total nurse aide's activities were spent by Messenger activities, 14.4% by Housekeeping activities, 2.2% by Nursing activities, 1.0% by Clerical activities, 0.83% by Administrative activities, and 44.94% by Unclassified activities, 2. Percentages of nursing activities were identified at each level of nursing personnel according to area of activity. 1) Thirty three point ninety six percent of the total head nurse's activities were spent by Unit - Centered activities, 30.26% by Patient - Centered activities, 8.69 % by Personnel - Centered activities and 24.09 o/o by Other - Centered activities. 2) Fifty two point seventy four percent of the total staff nurses' activities were spent by Patient - Centered activities, 11.5 % by Unit -Centered activities, 1.68 % by Personnel -Centered activities and 34.02% by Other - Centered activities. 3) Forty nine point sixty seven Percent of the total Nurse aide's activities were spent by Unit -Centered activities, 5.13% by Patient -Centered activities, 0.27% by Personnel -Centered activities and 44.93%by Other -Centered activities. 3. Percentages of staff nurses' activities were identified at each skill Level according to their shifts. 1) Forty four point eighty one percent of the total day time activities were spent by Nursing activities, 13.62% by Administrative activities, 6.37% by Housekeeping activities, 2.08% by Clerical activities, 1.74 % by Messenger activities, 0.07% by Dietary activities and31.31 o/o by Unclassified activities. 2) Thirty three point eighty seven percent of the total evening time activities were spent by nursing activities, 10.51% by Housekeeping activities, 10.0% by Administrative activities, 4.58% by Clerical activities, 2.46% by Messenger activities, 0.09% by Dietary activities and 38.49% by Unclassified activities, 4. There was no great difference among activities of 5 days.

• The KSFM Journal of Fluid Machinery
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• v.11 no.6
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• pp.7-17
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• 2008

Fan performances are obtained with various tip clearance gaps and stagger angles of the rotor. A tested fan is an axial-type fan of which the casing diameter is 806 mm. Two different rotors are applied to this test. One is designed on the basis of the free vortex method along the radial direction and the other is designed using the forced vortex method. The operating conditions are varied to the ultimate off-design point as well as the deign point. Overall efficiency, total pressure and input power are compared with the tip clearance gaps and different stagger angle. The experimental results show that changing of the stagger angle has minor influence to the performance when the same rotor is applied. When the tip clearance gap is less than 5% of the rotor span, the overall efficiency, total pressure loss and input power reduction are varied linearly with the variation of the tip clearance gaps. On the design point, the overall efficiency is decreased to the rate of 2.8-2.9 to the increasing of the tip clearance, but the changing rate of the overall efficiency is alleviated when the fan operates at off-design points. In particular, this rate is more quickly declined on a fan with the rotor designed using the forced vortex method. The result of the total pressure shows that the pressure reduction rate is a 0.08-0.1 according to the tip clearance, and additionally the input power reduction rate is a 0.045-0.065 at design point.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.7
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• pp.19-25
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• 1993

By using the point matching method, the coplanar waveguide shielded by the rectangular waveguide has been analyzed. The particular potential solution of C.P.W has been obtained from the boundary condition by using the point matching method. The line capacitance has been obtained from the total charge of the center conductor per length. The effective dielectric constant and the line impedance have been obtained from the line capacitance of C.P.W.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.226-235
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• 2000

Two representative finite volume methods, i.e., the time marching method and the pressure correction method, were applied to 8 centrifugal compressor impeller flows, with low to very high level of pressure ratio, among which 7 impellers' experimental performance is given in the open literature. The present study is focused on the prediction differences from both methods, developed by the authors, in the pressure correction method's point of view. In all cases, the time marching method gives a satifactory solution, but the pressure correction method does not. Up to about $18\%$ less level of total-to-total pressure ratio is predicted by the pressure correction method as the level of the impeller pressure ratio increases up to about 10. The drop of total pressure ratio is caused by the underestimation of static pressure rise which seems to be attributed to inappropriate linearization and discretization of the pressure/density coupling terms in the pressure correction equation.