• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.58-63
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• 2014

Most of light duty AGVs(AGCs) using tape of magnetic for the guide path have digital guidance magnetic sensor. Digital guidance magnetic sensor using magnet-tape is on/off type and has positioning error of magnet-tape as 10~50 mm. AGC using this sensor doesn't induce accurate position of magnet-line which is magnet-tape because of magnetic field which motor in AGC creates, outer magnetic field, earth's magnetic field, etc. AGC when driving wobbles due to this error and this error can cause path deviation. In this paper, we propose fuzzy inference system for improvement of bipolar analog magnetic guidance sensor performance. Fuzzy is suitable in term of fault tolerance, uncertainty tolerance, real-time operation, and Nonlinearity as compared with other algorithms. In previous research, we produced bipolar magnetic guidance sensor and we set the threshold in order to calculate digital values of magnet position. Fuzzy inference system is designed using outputs of Analog hall sensors. Magnet position calculated by digital method is improved by outputs of this system. In result, proposed method was verified by improving performance of magnetic guidance sensor.

• Korean Journal of Cleft Lip And Palate
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• v.4 no.2
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• pp.51-68
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• 2001

Midfacial hypoplasia in patients with clefts of the lip and palate is considered to be the result of congenital dysmorphogenesis. And cleft lip and palate developes facial deformity, jaw abnormality, speech problem, which is most frequent hereditary deformity in maxillofacial region. So cleft lip and palate is characterized by midface deformity which shaws maxillary anterior nasal septal deviation and deformity. Our study describes congenital correlates of midfacial hypoplasia by examining the displacement of a normal complement of parts, a triangular tissue deficiency low on the lip border on the columellar side, and a linear deficiency and displacement in the line of the bilateral cleft lip. 15 patients with bilateral cleft lip and palate were taken impression before operation, but the patient who had other abnormalities and complications were excluded. Average age is 3.4 months and they were classified into both complete, both incomplete and complete & incomplete group. The obtained results were as follows 1. There were no differences on intercanthal width and canthal width between each of the groups. 2. Both complete group had longer lateral ala length than both incomplete group, but there were no differences between both complete group and complete side of com. & incom. group and both incomplete group and incomplete side of com. & incom. group. 3. Columella length was greater in both incomplete group than in both complete group, but there was no difference between both complete group and complete side of com. & incom. group and both incomplete group and incomplete side of com. & incom. group. 4. Both complete group had longer ala width & ala base width than both incomplete group had. But there were no differences between both complete group and complete side of com. & incom. group and both incomplete group and incomplete side of com. & incom. group. 5. There were no differences between each of the groups on upper lip length, but nose/mouth width ratio was greater in both complete group than in both incomplete group. 6. Pronasale(pm), subnasle(sn), la~rale superioris(ls), stomion(sto) points were located around the central vertical line of face but deviated to incomplete side in com. & incom. group. 7. Nasal tip protrusion was greater in both incomplete group and com. & incom. group than both complete group, but there was no difference between both incomplete group and com. & incom. group.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.35-43
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• 2017

The purpose of this study was to analyze the converged influencing factors on the stages of exercise behavior changes in shift work nurses. The subjects were 120 shift work nurses working in hospitals who understood the purpose of the study and agreed to participate in the study. Data were analyzed using frequency, percentage, mean, standard deviation, t-test, $X^2$ test, and multiple logistic regression analysis. The exercise motivation factors of shift work nurses had a significant effect on stages of exercise behavior change (${\beta}=2.480$, p=.022), health status perceptions(${\beta}=1.151$, p=.013). Social support factors (${\beta}=1.819$, p=.002) and marital status (${\beta}=-1.820$, p=.004) also had significant effects on the stages of exercise behavior change of shift work nurses. In other words, subjects with change in exercise behavior had 11.9 times higher motivation and 3.1 times higher health status perception than those without change in exercise behavior, social support was 6.1 times higher, and unmarried subjects showed 16 times showed higher than that of married subjects. Therefore, it is important to develop a strategy to practice continuous and regular exercise in consideration of the exercise motivation, social support, and health status perception of the nurses in shift work.

• Journal of Korea Water Resources Association
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• v.48 no.6
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• pp.425-438
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• 2015

The objective of this study was to evaluate simulation of agricultural water supply considering yearly variation of irrigation efficiency. The water supply data of the Idong reservoir from 2001 through 2009 was collected and used for this study. Total 6 parameters including irrigation efficiency (Es), drainage outlet height, and infiltration, were used for sensitivity analysis, calibration, and validation. Among the parameters, the Es appeared to be the most sensitivity parameter. The Es was calibrated on a yearly basis considering sensitivity and time-varying characteristic, while other parameters were set to fixed values. The statistics of percent bias (PBLAS), Nash-Sutcliffe efficiency (NSE), and root means square error to the standard deviation of measured data (RSR) for a monthly step were 2.7%, 0.93, and 0.26 for the calibration, and 3.9%, 0.89, and 0.32 for the validation, correspondently. The results showed a good agreement with the observations. This implies that the modeling only with appropriate parameter values, apart from modeling approaches, can simulate the real supply operation reasonably well. However, the simulations with uncalibrated parameters from previous studies produced poor results. Thus, it is important to use calibrated values, and especially, we suggest the Es's yearly calibration for simulating agricultural water supply.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.80-87
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• 2016

In this work, we conduct a thermal pointing error analysis of the observation satellites considering seasonal and daily temperature variation with interpolated temperature based on prescribed average temperature (PAT) method. Maximum 200 degree temperature excursion is applied to the observation satellites during on-orbit operation, which cause the line of sight (LOS) to deviate from the designated pointing direction due to thermo-elastic deformation. To predict and adjust such deviation, the thermo-elastic deformation analysis with a fine structural finite element model is accomplished with interpolated thermal maps calculated from the results of on-station thermal analysis with a coarse thermal model. After verifying the interpolated temperatures by PAT with two benchmark problems, we evaluate the thermal pointing error.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.602-608
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• 2011

Purpose: Nasal bone fracture is the most common type of facial bone fracture and most of nasal bone fracture is combined with septal fracture frequently. Nasal septum is important to support the distal nose and to maintain the nasal airway. But nasal septal fractures are usually unrecognized and untreated at the time of operation. Recently, various materials were using for nasal packing after closed reduction, however these materials are not focused on the correction of nasal bone and nasal septal fracture and many patients are suffered from nasal packing materials. Thus, the purpose of this study is to compare routine packing materials and rolled silastic sheet with respect to postoperative effect of correction of nasal bone fracture and discomfort of nasal packing materials. Methods: We examined 320 patients treated nasal bone fracture from January 2008 to December 2010. For Group I (n=92), $Merocel^{(R)}$ was used for nasal packing, for Group II (n=152) vaseline gauze was used, and Rolled silastic sheet (RSS) with vaseline gauze packing (VGP) was used for Group III (n=76). Under the general anesthesia, all patients were operated by closed reduction and nasal packing was done using three kinds of packing materials. At the time of postoperative 7 days, packing material was removed and studied for pt's satisfaction and postop. complications. Results: In patients with RSS with VGP, the complaints (nasal obstruction, foreign compressive sensation and discomfort during food ingestion) of keeping the nasal packing were decreased ($p$ <0.05) and the postoperative complication (deviation) were decreased comparing to vaseline gauze packing and $Merocel^{(R)}$ packing, however, these differences were not statistically significant ($p$ >0.05). Conclusion: Postoperative nasal packing with RSS with VGP was more comfortable to the patients and it was more effective method to correct the nasal bone fracture and nasal septal fracture.

• Journal of KIISE:Information Networking
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• v.36 no.5
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• pp.413-424
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• 2009

Wireless sensor network is based on an event driven system. Sensor nodes collect the events in surrounding environment and the sensing data are relayed into a sink node. In particular, when events are detected, the data sensing periods are likely to be shorter to get the more correct information. However, this operation causes the traffic congestion on the sensor nodes located in a routing path. Since the traffic congestion generates the data queue overflows in sensor nodes, the important information about events could be missed. In addition, since the battery energy of sensor nodes exhausts quickly for treating the traffic congestion, the entire lifetime of wireless sensor networks would be abbreviated. In this paper, a new congestion control method is proposed on the basis of genetic algorithm. To apply genetic algorithm, the data traffic rate of each sensor node is utilized as a chromosome structure. The fitness function of genetic algorithm is designed from both the average and the standard deviation of the traffic rates of sensor nodes. Based on dominant gene sets, the proposed method selects the optimal data forwarding sensor nodes for relieving the traffic congestion. In experiments, when compared with other methods to handle the traffic congestion, the proposed method shows the efficient data transmissions due to much less queue overflows and supports the fair data transmission between all sensor nodes as possible. This result not only enhances the reliability of data transmission but also distributes the energy consumptions across the network. It contributes directly to the extension of total lifetime of wireless sensor networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.350-356
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• 2018

The contact force, which is the dynamic interaction between the pantograph and the catenary, is an important indicator for evaluating the current collecting quality, which is a stable power supply characteristic to the vehicle. In this study, dynamic contact force characteristics of pantograph of HEMU-430X vehicle, which is a power-distributed high-speed train test vehicle, were analyzed according to the catenary tension and compared with the analytical results using the pantograph-catenary interaction model. As a result of comparing the test results with the analytical results, it was confirmed that the average contact force and the standard deviation of the contact force, which are the main dynamic contact force characteristics, coincide relatively well. Using the analytical model, the relationship between the catenary tension and the contact force is presented according to the vehicle speed, and the optimal catenary tension for each operation speed is presented and compared with the international standard. As a result, it was found that the results obtained from the analysis are comparable to those recommended by international standards.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.127-136
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• 2019

Tunnel construction by TBMs should be supported by the performance of a screw conveyor in order to obtain the optimum penetration rate, so studies related to the screw conveyor performance have been being conducted. Compared to the study on the performance of the screw conveyor for the soil, however, the research on the performance of the screw conveyor for the rock is insufficient. Considering the domestic tunnel sites with more rock layers than soil layers, simulation of discharge of 6 types of rock chips by the screw conveyor was conducted using DEM. Regardless of the shape and volume of the rock chips, the discharge rates of the rock chips by the parallel placed screw conveyor at a speed of 10 RPM in the same rock mass were about 20% (standard deviation: 1.3%) of the maximum volume of discharge rate by the screw conveyor. It is expected that this study can be used as a reference material for screw conveyor design and operation in TBM excavations in rock masses.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.38-46
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• 2021

In the era of the 4th Industrial Revolution, the interest in autonomous ship technology is increasing as high-tech technologies are being increasingly utilized throughout the industry. Therefore, we conducted a basic study on autonomous ships. In particular, a passenger ship model was produced and an autonomous navigation system was established by applying the ardupilot used for drones. The possibility of automatic control of the autonomous ship operations was confirmed by executing various voyage plans using the built model ship. In the performance test for maintaining the course the model ship could not follow the designated course straight and sailed up to 5.4 m away from the course while navigating in a zigzag (S-shape); however, after the parameters were modified, the deviation distance was reduced to a maximum of 1.8 m. In the turning performance test, the maximum diameter of the turning sphere was found to be approximately 9.3 m, but no significant change could be confirmed even after the parameters were modified. However, the results of our tests on slowing down the ship before arriving at the WP confirmed that the diameter of the turning sphere was reduced to a maximum of approximately 3.2 m. In order to evaluate the stopping performance, the last scheduled stopping position of all experiments was compared with the actual stopping position of the model ship and it was confirmed that the model ship stopped at a point at least 0.4 m and a maximum of 6.2 m away from the stopping position. In the future, improvement of course stability, turning performance, and stopping performance is required through modification and supplementation of various parameters. Moreover, a study on automatic berthing of the model ship through automatic control is planned.