• Journal of the Korean Geotechnical Society
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• v.30 no.7
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• pp.27-40
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• 2014

So far, studies on the settlement of breakwater have mainly been conducted through numerical model tests focusing on an analysis or through the laboratory wave tank tests using a scaled model. There has not been a study on the settlement that is measured in an actual breakwater structure. This study analyzed the data of settlement that has been measured in an actual caisson breakwater for a long time and the characteristics and causes of wave-induced settlement in the caisson (including beneath ground), based on qualitative aspect, were examined. The analysis revealed that wave clearly has an effect on the settlement in caisson, especially in the condition of high wave such as typhoon. Caisson settlement is caused by the liquefaction of ground, which is due to the increase of excess pore pressure, the combination of oscillatory excess pore pressure and residual excess pore water pressure, and the solidification process of ground due to dissipation of the accumulated excess pore pressure. The behavior of excess pore pressure in the ground beneath the caisson is entirely governed by the behavior of the caisson. Ground that has gone through solidification is not likely to go through liquefaction in a similar or a smaller wave condition and consequently, the possibility of settlement is reduced.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.6
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• pp.274-282
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• 2013

Objectives: The posterior maxillary region often provides a limited bone volume for dental implants. Maxillary sinus elevation via inserting a bone graft through a window opened in the lateral sinus wall has become the most common surgical procedure for increasing the alveolar bone height in place of dental implants in the posterior maxillary region. The purpose of this article is to assess the change of bone volume and the clinical effects of dental implant placement in sites with maxillary sinus floor elevation and autogenous bone graft through the lateral window approach. Materials and Methods: In this article, the analysis data were collected from 64 dental implants that were placed in 24 patients with 29 lacks of the bone volume posterior maxillary region from June 2004 to April 2011, at the Department of Oral and Maxillofacial Surgery, Inha University Hospital. Panoramic views were taken before the surgery, after the surgery, 6 months after the surgery, and at the time of the final follow-up. The influence of the factors on the grafted bone material resorption rate was evaluated according to the patient characteristics (age and gender), graft material, implant installation stage, implant size, implant placement region, local infection, surgical complication, and residual alveolar bone height. Results: The bone graft resorption rate of male patients at the final follow-up was significantly higher than the rate of female patients. The single autogenous bone-grafted site was significantly more resorbed than the autogenous bone combined with the Bio-Oss grafted site. The implant installation stage and residual alveolar height showed a significant correlation with the resorption rate of maxillary sinus bone graft material. The success rate and survival rate of the implant were 92.2% and 100%, respectively. Conclusion: Maxillary sinus elevation procedure with autogenous bone graft or autogenous bone in combination with Bio-Oss is a predictable treatment method for implant rehabilitation.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.2
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• pp.179-190
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• 2012

The installation of an implant in the distal extension area to assist a partial dentrue (IARPD) was used carefully in clinical situations. The purpose of this review on the IARPD is describing the concept, clinical results and guidelines of IARPD. For the review, a literature search was performed using the PubMed. The data from the literature suggest that the placement of the implants could improve function and patient satisfaction. In addition, IARPD reduced the residual ridge resorption. Longer and wider implant should be placed. Less than $15^{\circ}$ angulation may be not harmful. To prevent the loosening of the abutment, modified abutment or resilient attachment should be used. However, the connection method between the clasp retention and IARPD should be considered for long time success. Moreover, longitudinal clinical studies are required for evaluation of IARPD.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.23-33
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• 2020

Recently, high-resolution images can be easily acquired using UAV (Unmanned Aerial Vehicle), so that it is possible to produce small area observation and spatial information at low cost. In particular, research on the generation of cover maps in crop production areas is being actively conducted for monitoring the agricultural environment. As a result of comparing classification performance by applying RF(Random Forest), SVM(Support Vector Machine) and CNN(Convolutional Neural Network), deep learning classification method has many advantages in image classification. In particular, land cover classification using satellite images has the advantage of accuracy and time of classification using satellite image data set and pre-trained parameters. However, UAV images have different characteristics such as satellite images and spatial resolution, which makes it difficult to apply them. In order to solve this problem, we conducted a study on the application of deep learning algorithms that can be used for analyzing agricultural lands where UAV data sets and small-scale composite cover exist in Korea. In this study, we applied DeepLab V3 +, FC-DenseNet (Fully Convolutional DenseNets) and FRRN-B (Full-Resolution Residual Networks), the semantic image classification of the state-of-art algorithm, to UAV data set. As a result, DeepLab V3 + and FC-DenseNet have an overall accuracy of 97% and a Kappa coefficient of 0.92, which is higher than the conventional classification. The applicability of the cover classification using UAV images of small areas is shown.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.863-868
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• 2016

In this study, the precise shapes of sunken ships and information on seafloor topography were analyzed using data obtained from a multi-beam echo sounder. The state of each sunken ship was analyzed by processing diverse imagery data which was compared with data obtained from past investigations to determine changes in the state and circumjacent seafloor topography. Apparent changes in the seafloor topography around one sunken ship, the "Pacific Friend", were found from stern to bow as a result of continued submarine erosion and sedimentation. In the case of sunken ship "No. 7 Haeseong", the partial collapse of the bow was revealed in the seabed images captured in 2015, though it had still been intact in images captured during the Korea Hydrographic and Oceanographic Agency's investigation in 2011. This partial collapse was presumed to have resulted from the effects of continued tidal currents, the cargo load of the ship and continued corrosion of the ship over a long time on the seabed. Continuous monitoring of residual fuel inside the ship is necessary to avoid leakage and potential marine pollution. By conducting image analysis on these sunken ships, it has been determined that the structural safety of the ships is seriously influenced by tidal currents and seafloor topography, while the hulls will be continuously changed by corrosion. As a result, it can be concluded that the development of prediction and response techniques that take into consideration residual fuel leakage and environmental changes according to the geological characteristics of sunken ships is necessary.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.258-261
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• 1991

In order to establish the optimum drying temperature of the heated air blast-grain circulation dryer, a 2 ton scale of paddy was used in this experiment. The temperatures of heated air used were 45, 50, 55, 60, 65 and $70^{\circ}C$. Moisture content of the paddy was reduced to 15% from 24% by drying. The higher air temperature, the shorter drying time and the less fuel consumed. The portion of cracked kernels was found to be low as $3{\sim}10%\;at\;40{\sim}55^{\circ}C$, but was very high to $28{\sim}30%\;at\;60{\sim}70^{\circ}C$. The germination percent was very high as 98 and 93% at 40 and $45^{\circ}C$, but it was decreased to 86 and 30% at 50 and $70^{\circ}C$, respectively. The recovery yield of milled rice from paddy was decreased by 1.76, 2.63 and 7.52% at 60, 65 and $70^{\circ}C$, respectively, compared with 75.86% as drying at $40^{\circ}C$. The higher heated air temperature, the less head rice of milled rice was recovered, and the decreased ratio was increased $60^{\circ}C$. The higher heated air temperature, the less alkali disintergation value and gel consistency of milled rice and the more water up take, expanded vlume, total solid in residual liquid and intensity of starch iodine blue value of residual liquid, and those tendency was found clear from $60^{\circ}C$ temperature of heated air.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.148-155
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• 2014

The transfer pattern of chlorpyrifos present in soil to cucumber plants were assessed and reported with plant growth, concentration dependency, and duration. Cucumber seedlings cultivated in a growth chamber for 30 days and a greenhouse for 120 days. Weight and length of cucumbers cultivated in the chamber increased with the increasing time, while the uptake of chlorpyrifos by cucumber increased a period from 0 to 15 days and decreased after 15 days. Uptake rates of chlorpyrifos into a cucumber plant were 1.0~1.3% to initial amounts treated with 20 and 40 mg/kg to soil. Most chlorpyrifos residues were detected in root, followed by stem and leaf. Results of the greenhouse test showed that chlorpyrifos amounts in cucumber fruits were present less than LOQ (0.02 mg/kg), and chlorpyrifos was mainly found in the root of the cucumber plant. Chlorpyrifos absorbed in a cucumber under greenhouse condition was smaller than that in chamber condition as 0.03~0.04%. Degradation patterns of chlorpyrifos in soils were similar during indoor and outdoor tests with half-lives of 25.8~73.0 days. These results may be useful for establishing the management strategy of residual pesticides in soil environment.

• Journal of Digital Convergence
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• v.17 no.12
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• pp.393-398
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• 2019

This study aimed to suggest the optimum number of rinsing by researching changes in optical density and pH in accordance with the number of rinsing after toothbrushing, and then verifying the amount of residual toothpaste in mouth. Total 14 university students who had healthy body with no difficulties in daily life were selected from the students of K university in Daegu as the research subjects. The research subjects rinsed their mouths with 40ml of water from zero time to 12 times after toothbrushing. After collecting each rinsing water, the optical density and pH were measured. In the results of measuring the optical density value of each rinsing water, the rinsing water of six-seven times or more after toothbrushing showed the constant value of optical density, which was statistically significant(p<0.05). There were no differences in accordance with the amount of toothpaste such as 1g, 1.5g, and 2g. Based on such results of this study, it would be necessary to provide the education of the use of dentifrice, and also to have diverse researches on the effects of residual dentifrice in mouth on the oral cavity.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.4
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• pp.177-190
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• 2016

In case of the seabed around and under gravity structures such as submerged breakwater is exposed to a large wave action long period, the excess pore pressure will be generated significantly due to pore volume change associated with rearrangement soil grains. This effect will lead a seabed liquefaction around and under structures as a result from decrease in the effective stress. Under the seabed liquefaction occurred and developed, the possibility of structure failure will be increased eventually. Lee et al.(2016) studied for regular waves, and this study considered for irregular waves with the same numerical analysis method used for regular waves. Under the condition of the irregular wave field, the time and spatial series of the deformation of submerged breakwater, the pore water pressure (oscillatory and residual components) and pore water pressure ratio in the seabed were estimated and their results were compared with those of the regular wave field to evaluate the liquefaction potential on the seabed quantitatively. Although present results are based on a limited number of numerical simulations, one of the study's most important findings is that a more safe design can be obtainable when analyzing case with a regular wave condition corresponding to a significant wave of irregular wave.

• Journal of the Korea Society of Computer and Information
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• v.18 no.6
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• pp.29-36
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• 2013

In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. Most of the existing energy efficient routing protocols use the minimum energy path to minimize energy consumption, which causes an unbalanced distribution of residual energy among nodes. As a result, the power of nodes on energy efficient paths is quickly depletes resulting in inactive. To solve these problems, a method to equalize the energy consumption of the nodes has been proposed, but do not consider the link error rate in the wireless environment. In this paper, we propose a uniform energy consumption of cluster-based multi-hop routing mechanism considering the residual energy and the link error rate. This mechanism reduces energy consumption caused by unnecessary retransmissions and distributes traffic evenly over the network because considering the link error rate. The simulation results compared to other mechanisms, the proposed mechanism is energy-efficient by reducing the number of retransmissions and activation time of all nodes involved in the network has been extended by using the energy balanced path.