• Journal of the korean academy of Pediatric Dentistry
• /
• v.34 no.3
• /
• pp.481-489
• /
• 2007

Maxillary canine impaction is a frequently encountered clinical problem, and it may cause the resorption of adjacent tooth or cystic change. Treatment plan for maxillary canine impaction should be decided among extraction, orthodontic traction and autotransplantation according to several factors such as direction and position of unerupted tooth, degree of developing root apex, eruption space, exsitance of supernumerary tooth, odontoma, or cyst. Autotransplantation is a valuable alternative to extraction of impacted teeth, where surgical exposure and subsequent orthodontic realignment are difficult or impossible due to unfavorable impaction position. And its prognosis is dependent on a number of factors such as preservation of periodontal ligament, degree of root development, surgical technique, patient's age, endodontic treatment, time and type of splinting and storage medium, etc. The patients in these cases visited our dental clinic in the late permanent dentition with the chief complaint of unerupted maxillary canines. And it was thought that the spontaneous eruption guidance or orthodontic traction and alignment were difficult because of its unfavorable impacted position. Therefore, autotransplantaion and endodontic treatment were done and have been checked periodically until now.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.2
• /
• pp.485-495
• /
• 2017

A development of underground space is very useful solution to slove problem occurred from ground surface enlargement in urban areas due to the growth of population, tunnelling is the most popular way and widely used. Researches regarding tunneling-induced pile-soil interactive behaviour have been conducted by many researchers. A study on pile axial force distribution due to tunnelling through laboratory model test, however, is being rarely carried out. In this study, therefore, authors investigate ground behaviour due to tunnelling below grouped pile subjected vertical load as well as pile axial force distribution. A concept of volume loss is used to express tunnel excavation, which is normally applied to 1~2% for tunnelling in soft ground. In this study, however, 10% of that applied to investigate failure mechanism. As a result of laboratory model test, a decrease of pile axial force occurs at 1.5% of volume loss, settlement of grouped pile is 1.2~4.7 times greater than the adjacent ground surface one. Ground deformations at 1.5% of volume loss are measured using Close Range Photogrammetry and compared with results from numerical analysis.

• Explosives and Blasting
• /
• v.28 no.2
• /
• pp.17-27
• /
• 2010

With the development of modern society, there have been great technical advances, and the meaning, shape, and type of preservation objects have also become diverse. However, the legislation of executives established in 1961 has nt yet been revised realistically. Thatses administrative problems related to the usge and storage of explosives. In this study, the cases of civilian's question and thought that had been submitted to the government agency were surveyed. In order to analyze the effects of preservation object, ENPro3.1, which is a simulation program to analyze the sound pressure, was used to estimate the blast pressure when a magazine containing preservation objects exploded. With the damage due to the blast pressure, the problem with the safe distance depending on the preservation object levels was investigated. From the investigation, the blast pressures in the two cases with the artificial structures at the real distance 309 m and without the artificial structures at the legitimate standard space distance 440 m, were found to be 123 dB(L) and 138 dB(L), respectively. That means the influence of blast pressure in shorter distance with artificial structures is 15 dB(L) lower than longer distance without them. Therefore, it is recommended to apply the preservation distance based on the engineering analysis with a consideration of surrounding environment.

• Journal of Internet Computing and Services
• /
• v.18 no.3
• /
• pp.19-28
• /
• 2017

Collaborative filtering (CF) is a system that interprets the relationship between a user and a product and recommends the product to a specific user. The CF model is advantageous in that it can recommend products to users with only rating data without any additional information such as contents. However, there are many cases where a user does not give a rating even after consuming the product as well as consuming only a small portion of the total product. This means that the number of ratings observed is very small and the user rating matrix is very sparse. The sparsity of this rating data poses a problem in raising CF performance. In this paper, we concentrate on raising the performance of latent factor model (especially SVD). We propose a new model that includes product similarity information and co occurrence information in SVD. The similarity and concurrence information obtained from the rating data increased the expressiveness of the latent space in terms of latent factors. Thus, Recall increased by 16% and Precision and NDCG increased by 8% and 7%, respectively. The proposed method of the paper will show better performance than the existing method when combined with other recommender systems in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.5
• /
• pp.495-503
• /
• 2014

As the number of vehicles has been sharply increases, the significance of safety and effective operation issues in the parking lot is being emphasized, which takes a part of the transportation system. Recently, there have been several studies for the parking management by detecting moving object, however, recognizing numbers of fast-moving vehicles simultaneously in the picture is still a challenging problem. The parking lot in public area, or large-sized buildings has clear parking section, whereas the sensor system is configured to monitor a plurality of parking spaces. Therefore, by considering those parking lots, we suggested to develop the real-time parking availability information system by applying the real-time image processing techniques. with the help of template matching. Following the study, we wanted to provide the alternative method for parking management system through the reference template makers by recognizing movements of parked vehicles with the size and shape, regardless of direct detecting of driving movements. In addition, we evaluated the applicability and performances of the information system, presented in this study, and implemented a prototype system to simulate the parking statuses of each floor. In fat, it was possible to manage and analyze statistics about the total number of parking spaces and the number of vehicles parked through real-time video flames. We expected that the result of the study will be advanced, following the user-friendliness and cost reduction in operating parking management system and giving information by efficient analysis of parking situation.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.30 no.1
• /
• pp.67-76
• /
• 2010

The purpose of this study was to suggest the growth characteristics, seasonal anthesis distribution and botanical composition of wildflower pasture. The experimental wildflower were 34 species (1 turfgrass species, 4 native wildflower species and 29 introduced wildflower species). The experiment were administered in the Chungnam National University experimental field from March, 2008 to December, 2009 and the result is as follows: the wildflower length were within the range of 8-60 cm and their up-and-down space arrangement quite good. They bloomed into several colors of nine but one or three of nine colors were biased during August, September, and October. Their anthesis was biased toward May and June, and their seasonal distribution and permanence maintenance were too difficult from August and moreover two years later (2009) because of the decrease of the botanical distribution of annual wildflower after winter, the color, seasonal distribution, and permanence of wildflower became a problem. The botanical composition of wildflower, turf grass, and weeds came to 24%, 62%, and 14% each one year later (2008) and two years later (2009) 16%, 69%, and 15% each. Being grounded upon this result, in case of wildflower pasture of spring seeding, it is more important to maintain the color, seasonal distribution, and permanence of wildflower two years later than in the establishment year.

• Tunnel and Underground Space
• /
• v.26 no.2
• /
• pp.110-119
• /
• 2016

The purpose of this study is to evaluate the applicability of tailing in the ${\bigcirc}{\bigcirc}$ mine as a grout material. For the purpose, XRD analysis was performed for mineralogical properties of tailing. In addition, flow, velocity, and uniaxial compressive strength tests were carried out for physical and mechanical properties of a grout material with the mixing ratio of cement and tailing and curing periods. By the result of XRD analysis, tailing of the mine was found to mostly consist of quartz, galena, and pyrite. The flow observed by the flow test showed decreasing tendency with increasing the mixing ratio of tailing. The velocity was also lowered with increasing the mixing ratio of tailing regardless of curing periods. The uniaxial compressive strength as well as Young's modulus also show a tendency to decrease with increasing the mixing ratio of tailing independently on the curing periods. Considering only the physical and mechanical properties of a grout material with tailing, the results are considered to be sufficiently used as a grout material. However, since metallic minerals such as galena and pyrite in tailing contents and these are causing environmental contamination, countermeasures should be considered for this problem in future.

• Korean Journal of Remote Sensing
• /
• v.33 no.6_3
• /
• pp.1215-1221
• /
• 2017

SeNtinel's Application Platform (SNAP) is an open source software developed by the European Space Agency and consists of several toolboxes that process data from Sentinel satellite series, including SAR (Synthetic Aperture Radar) and optical satellites. Among them, S1TBX (Sentinel-1 ToolBoX)is mainly used to process Sentinel-1A/BSAR images and interferometric techniques. It provides flowchart processing method such as Graph Builder, and has convenient functions including automatic downloading of DEM (Digital Elevation Model) and image mosaicking. Therefore, if computer memory is sufficient, InSAR (Interferometric SAR) and DInSAR (Differential InSAR) perform smoothly and are widely used recently in the world through rapid upgrades. S1TBX also includes existing SAR data processing functions, and since version 5, the processing capability of KOMPSAT-5 has been added. This paper shows an example of processing the interference technique of KOMPSAT-5 SAR image using S1TBX of SNAP. In the open mine of Tavan Tolgoi in Mongolia, the difference between DEM obtained in KOMPSAT-5 in 2015 and SRTM 1sec DEM obtained in 2000 was analyzed. It was found that the maximum depth of 130 meters was excavated and the height of the accumulated ore is over 70 meters during 15 years. Tidal and topographic InSAR signals were observed in the glacier area near Jangbogo Antarctic Research Station, but SNAP was not able to treat it due to orbit error and DEM error. In addition, several DInSAR images were made in the Iraqi desert region, but many lines appearing in systematic errors were found on coherence images. Stacking for StaMPS application was not possible due to orbit error or program bug. It is expected that SNAP can resolve the problem owing to a surge in users and a very fast upgrade of the software.

• Korean Security Journal
• /
• no.36
• /
• pp.29-55
• /
• 2013

In modern society, citizen's expectation about policing levels have been rising over time and it limited resources of the police to deal with the security services are insufficient. Until now, the state monopoly of the police activity was changing to subject of a variety in cooperation with public security system. The citizens considers community not the destination to police enforce the law but space for effective policing partners. Japanese police focus on cooperation oriented policing to strengthen the police and local residents with crime prevention for a long time. Also, the community through a variety of problem-solving policing activities to identify problems such as anxiety and anguish of the people. The legal basis for cooperative policing activity is that Nagaoka city crime prevention regulation in 1979. In recent years, Tokyo local government legislated the safe town development regulations(東京都安全 安心まちづくり條例) and set up the hot-spot area to promote the safety of public facilities. Cooperative policing not police intervention for crime prevention but national policy for the city reclamation in Japan. Police as well as the Ministry of Land and Transport, Ministry of Justice, Ministry of Education, Prime Minister and all government departments thread safe city, crime prevention, and has been working to make the safe city. Japan's cooperative policing is a system that receives the most attention and greater implications.

• Journal of Korea Water Resources Association
• /
• v.44 no.7
• /
• pp.565-576
• /
• 2011

Within a basin, there are potentially multiple locations that can be used as a washland, given their relatively small size when compared with other hydraulic facilities such a dam. However, it is unreasonable to install washlands in all these potential locations due to economic and environmental considerations. In this study, a new methodology for determination of installation priority of washlands is presented. How to integrate the decision variables in this decision making problem has been a key issue in previous studies because a washland can provide many benefits such as flood reduction, agricultural benefit and recreational benefit. In particular, a methodology is needed to integrate all decision variables realistically, properly and reasonably, in situations where there is not sufficient data for direct integration of all these decision variables such as construction cost or benefits a washland can provide. This new methodology aims to suggest how to integrate methodologies used in previous studies. The suggested methodology uses four different rankings which are determined based on a flood reduction effect, a relative significance index, an economic analysis, and a space planning suitability index. These rankings are integrated to determine a final installation priority ranking of washlands by a multi-dimensional scaling method. The new methodology has been applied to the Anseong river basin, to show its applicability, and the application result compared with those of previous studies.