• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.176-187
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• 2024

Recently, automated solutions using collaborative robots have been emerging in various industries. Their primary functions include Pick & Place, Peg in the Hole, fastening and assembly, welding, and more, which are being utilized and researched in various fields. The application of these robots varies depending on the characteristics of the grippers attached to the end of the collaborative robots. To grasp a variety of objects, a gripper with a high degree of freedom is required. In this paper, we propose a service automation system using a multi-degree-of-freedom gripper, collaborative robots, and vision sensors. Assuming various products are placed at a checkout counter, we use three cameras to recognize the objects, estimate their pose, and create grasping points for grasping. The grasping points are grasped by the multi-degree-of-freedom gripper, and experiments are conducted to recognize barcodes, a key task in service automation. To recognize objects, we used a CNN (Convolutional Neural Network) based algorithm and point cloud to estimate the object's 6D pose. Using the recognized object's 6d pose information, we create grasping points for the multi-degree-of-freedom gripper and perform re-grasping in a direction that facilitates barcode scanning. The experiment was conducted with four selected objects, progressing through identification, 6D pose estimation, and grasping, recording the success and failure of barcode recognition to prove the effectiveness of the proposed system.

• Journal of Korean society of Dental Hygiene
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• v.13 no.6
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• pp.925-932
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• 2013

Objectives : The purpose of the study is to improve autonomous decision-making ability by analyzing the relationship between autonomy and decision-making ability. Methods : The subjects were 176 dental hygienists in Busan. Self-reported questionnaire was fill out from May 2012 to January 2013. Results : The average of the degree of autonomy was $2.20{\pm}0.29$. Buddhists showed the highest score of $2.37{\pm}0.37$ (p<0.05). Buddhists had the higher education than other religions (p<.05). Clinical decision-making ability was $2.21{\pm}0.25$. Among the subcategories, statistically significant differences (p<.05) was shown by gender, degree of education, and religion in the domain of "Exploration of Choice and Alternatives"; Buddhists showed a higher score in the domains of "Assessment and Re-evaluation of Decisions" and "Review of Values and Goals," with significant difference of p<.05. Autonomy and clinical decision making revealed a positive correlation in the categories "Assessment and Re-evaluation of Decisions" (r=.518, p=.000), "Review of Values and Goals" (r=.610, p=.000), and "Investigation of Information and Synchronization of New Information" (r=.314, p=.000). Conclusions : To improve the performance of dental hygienists, working systems and training will be intensified to develop the autonomy and clinical decision making.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.1
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• pp.1-9
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• 2021

In the present study, the model-scale Propeller Open Water (POW) tests for the propeller of 176K bulk carrier and 8600TEU container ship were conducted through Computational Fluid Dynamics (CFD) simulation. In order to solve the incompressible viscous flow field, the Reynolds-averaged Navier-Stokes (RaNS) equations were employed as the governing equations. The γ-Reθ(gamma-Re-theta) transition model combined with the SST k-ωturbulence model was introduced to describe the laminar-turbulence transition considering the low Reynolds number of model-scale. Firstly, the flow simulation developing over a flat plate was performed to verify the transition modeling, in which the wall shear stresses were compared with experiments and other numerical results. Then, to investigate the effect of the model, the CFD simulation for the POW test was performed and the simulated propeller performance was validated through comparison with the experiment conducted at Korea Research Institute of Ships & Ocean Engineering (KRISO).

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2660-2665
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• 2007

Turbulent boundary-layer over a micro-riblet film(MRF) was investigated experimentally. The MRF has sharp V-shaped micro scale grooves of $300{\mu}m$ in width and $176.8{\mu}m$ in height. Particle image velocimetry(PIV) system was employed to measure velocity fields of flow over the MRF coated plate. Flow over a smooth plate was also measured for comparison. The PIV measurements were taken in the streamwise wall-normal planes at Re$\theta$= 985 and 2342. Vortex structures of the flow were analyzed by extracting the swirling strength as an unambiguous vortex-identification criterion. As a result the number of spanwise vortices with clockwise(negative) rotation decreases rapidly in the near-wall region(y<0.2h), but decreases slowly in the outer region(0.2h

• Journal of the Korean Dietetic Association
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• v.14 no.2
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• pp.176-185
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• 2008

The purpose of this study was to identify school dieticians' perceptions on the Potentially Hazardous Food (PHF) and the inspection of food safety and sanitation conducted by Provincial Office of Education. Questionnaires were distributed to 400 school dieticians in elementary schools in Seoul and Gyeonggi Province, and 217 responses were collected. The majority of respondents (64%) defined PHF as food that easily decays at room temperature and over half of the respondents considered Korean cooked vegetables as a PHF. In addition, 4% of respondents completely excluded PHFs from their menus. Forty five percent of the respondents selected CCP rule 7 (delivery and distribution process) and 34% selected CCP rule 6 as the most difficult of the CCP rules to follow. Also, perceptions concerning food safety inspection and sanitation were not high in terms of validity, objectivity, and reliability among the evaluation criteria. The study results suggest that PHF as well as Potentially Hazardous Menu (PHM) definitions and guidelines should be re-established in consideration of traditional Korean food culture and the preparation of Korean foods.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.173-176
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• 2009

The Arbitrary Lagrangian-Eulerian(ALE, in short) method is the new description of continum motion, which combines the advantages of the classical kinematical descriptions, i.e. Lagrangian and Eulerian description, while minimizing their respective drawbacks. In this paper, the ALE description is adapted to simulate fluid-structure interaction problems. An automatic re-mesh algorithm and a fluid-structure coupling process are included to analyze the interaction and moving motion during the 2-D axisymmetric solid rocket interior FSI phenomena simulation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1380-1390
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• 1999

To assess the food intake and diet quality of preschool children in Pusan, dietary survey was conducted with 176 subjects using 24hr recall method. Diet quality was assessed by food group pattern, dietary diversity score(DDS), dietary variety score(DVS), and dietary frequency score(DFS). The total number of food items consumed was 307. The foods consumed most frequently were rice, Korean cabbage kimchi, milk and green onion. When investigating the consumption pattern of major six food groups, 38.1% of subjects consumed all six groups. Food group was missed in order of fruit(41.5%), sweet(19.9%), dairy(16.5), vegetable(4.5%) and meat(1.7%). The mean values of DDS, DVS, and DFS were 5.16, 13.82, and 16.07 re spectively. Persons who had higher DDSs also had higher DVSs(p<0.001). DDS, DVS and DFS correlated positively with NAR(nutrient adequacy ratio) and MAR(mean adequacy ratio) significantly. Associations between the NAR of most nutrients and MAR with DVS and DFS were higher than those between the NAR of most nutrients and MAR with DDS. People with DDS of above 6 or DVS of above 16 or DFS of above 21 met two thirds of recommended dietary allowance for nutrients. Based on the result of the food group intake, the food intake of subjects was not adequate, especially the fruit and dairy groups. When assessing the dietary quality of subjects using DDS, DVS and DFS, many people appeared not to have a desirable food intake.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.176-197
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• 1962

Seasonal variations of chemical constituents of estuarine water at a definite station of the tidal flat in Guang Yang inlet have been determined for two days a month. The range and mean of the annual variations are as follows:Tidal variations through a year are as follows:1. Although the tidal value of pH is almost constant during one tidal cycle, it raises abruptly 0.1-0.2 intervals of pH value during the first period of flood.2. The lower values of chlorinity, magnesium and calcium contents have been determined the nearer the slack after ebb, and slightly higher during the first period of flood tide than the last of ebb. The tidal change of calcium contents is more remarkable than of magnesium.3. The higher per cent saturation values of dissolved oxygen, sometimes higher than 100 per cent, re determined the nearer the slack after ebb.4. The total nitrogen contents, relatively poor, varies accidentally during one tidal cycle, whereas phosphate-P and silicate-Si are rich at the slack after ebb and increase proportionally to the mixing percentage of fresh water. The average values, 52.2 and 18.5 of Si/P and N/P are greater than of the normal.5. The acid soluble iron contents, lower in winter than in summer, is also varies accidentally during one tidal cycle and the magnitude of the variation is large.6. The chemical composition considered from the value of Ca/Cl or Mg/Cl of estuarine water varies according to the chlorinity even at the high chlorinity of 18-19%.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.176-183
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• 2003

This paper presents a neural network based approach to disseminating information relating to experimental and field observations in engineering. Although the methodology is generic and can be applied to many areas of engineering science, attention is focussed here solely on geotechnical engineering applications. Field data relating to the settlement of foundations presented by Burland and Burbidge (1985) which led to their well known equation for calculation of settlement, now included in most text books, is re-visited. A part of the data, chosen randomly, is used to train an Artificial Neural Network (ANN), which relates foundation settlement to various causes as identified by the authors. Predictions are made for situations for which data were not used in training. These indicate sufficient accuracy when compared to the original field data. Accuracy of predictions is further improved when all the data are included in the training set. The finally trained ANN is shown to represent these data more accurately than the Burland and Burbidge equation. Based on the above heuristic example, an ANN is presented as an alternative to developing equations and design rules in geotechnical engineering practice. Significant advantages are shown to arise by using this methodology. Ease of updating the ANN, as and when additional data becomes available, being the most important one. Loss of transparency, however, seems to be the main disadvantage.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.4
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• pp.168-176
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• 2000

This paper presents the Hessenberg method, a new sparsity-based small signal stability analysis program for large interconnected power systems. The Hessenberg method as well as the Arnoldi method computes the partial eigen-solution of large systems. However, the Hessenberg method with pivoting is numerically very stable comparable to the Householder method and thus re-orthogonalization of the krylov vectors is not required. The fractional transformation with a complex shift is used to compute the modes around the shift point. If only the dominant electromechanical oscillation modes are of concern, the modes can be computed fast with the shift point determined by Fourier transforming the time simulation results for transient stability analysis, if available. The program has been successfully tested on the New England 10-machine 39-bus system and Korea Electric Power Co. (KEPCO) system in the year of 2000, which is comprised of 791-bus, 1575-branch, and 215-machines. The method is so efficient that CPU time for computing five eigenvalues of the KEPCO system is 3.4 sec by a PC with 400 MHz Pentium IIprocessor.