• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.232-238
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• 2007

In this research, we constructed a 3D riverbed surveying system that is able to acquire the topographical information of a riverbed in real-time. The system consists of a RTK-GPS receiver and a echo sounder for collecting simultaneously the position and the water depth information of riverbed. A program for data composition and transformation was designed to generate the 3D coordinates by combining data of a GPS receiver and a echo sounder and made GIS database construction easy. We extracted TIN, digital elevation model and cross sectional maps of the riverbed by using GIS software from 3D data constructed through test surveying. It was shown that the accuracy of the result was RMS error of 0.069m when compared with the existing methods which use a total station and staffs. It is expected that the 3D riverbed surveying system wiil be able to be utilized to various surveying for water resources management in rivers, sea, dams, storing reservoirs and so forth.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.81-90
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• 2007

The effort identifying positioning information of the moving object in real time has been a issue not only in sport biomechanics but also other academic areas. In order to solve this issue, this study tried to track the movement of a pitched ball that might provide an easier prediction because of a clear focus and simple movement of the object. Machine learning has been leading the research of extracting information from continuous images such as object tracking. Though the rule-based methods in artificial intelligence prevailed for decades, it has evolved into the methods of statistical approach that finds the maximum a posterior location in the image. The development of machine learning, accompanied by the development of recording technology and computational power of computer, made it possible to extract the trajectory of pitched baseball from recorded images. We present a method of baseball tracking, based on object tracking methods in machine learning. We introduce three state-of-the-art researches regarding the object tracking and show how we can combine these researches to yield a novel engine that finds trajectory from continuous pitching images. The first research is about mean shift method which finds the mode of a supposed continuous distribution from a set of data. The second research is about the research that explains how we can find the mode and object region effectively when we are given the previous image's location of object and the region. The third is about the research of representing data into features that we can deal with. From those features, we can establish a distribution to generate a set of data for mean shift. In this paper, we combine three works to track baseball's location in the continuous image frames. From the information of locations from two sets of images, we can reconstruct the real 3-D trajectory of pitched ball. We show how this works in real pitching images.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.1
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• pp.71-79
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• 2014

Most researches have created the impervious surface map by using low-spatial-resolution satellite imagery and are inefficient to generate the object-based impervious map with a broad area. In this study, segment-based impervious surface mapping algorithm is proposed using the RapidEye satellite imagery in order to map impervious area. At first, additional bands are generated by using TOA reflectance conversion RapidEye data. And then, shadow and water class are extracted using training data of converted reflectance image. Object-based impervious surface can be generated by spectral mixture analysis based on land cover map of Ministry of Environment with medium scale, in the case of other classes except shadow and water classes. The experiment shows that result by our method represents high classification accuracy compared to reference data, quantitatively.

• Atmosphere
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• v.20 no.2
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• pp.111-130
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• 2010

An uncertainty assessment for precipitation datasets simulated by Atmosphere-Ocean Coupled General Circulation Model (AOGCM) is conducted to provide reliable climate scenario over East Asia. Most of results overestimate precipitation compared to the observational data (wet bias) in spring-fall-winter, while they underestimate precipitation (dry bias) in summer in East Asia. Higher spatial resolution model shows better performances in simulation of precipitation. To assess the uncertainty of spatiotemporal precipitation in East Asia, the cyclostationary empirical orthogonal function (CSEOF) analysis is applied. An annual cycle of precipitation obtained from the CSEOF analysis accounts for the biggest variability in its total variability. A comparison between annual cycles of observed and modeled precipitation anomalies shows distinct differences: 1) positive precipitation anomalies of the multi-model ensemble (MME) for 20 models (thereafter MME20) in summer locate toward the north compared to the observational data so that it cannot explain summer monsoon rainfalls across Korea and Japan. 2) The onset of summer monsoon in MME20 in Korean peninsula starts earlier than observed one. These differences show the uncertainty of modeled precipitation. Also the comparison provides the criteria of annual cycle and correlation between modeled and observational data which helps to select best models and generate a new MME, which is better than the MME20. The spatiotemporal deviation of precipitation is significantly associated with lower-level circulations. In particular, lower-level moisture transports from the warm pool of the western Pacific and corresponding moisture convergence significantly are strongly associated with summer rainfalls. These lower-level circulations physically consistent with precipitation give insight into description of the reason in the monsoon of East Asia why behaviors of individually modeled precipitation differ from that of observation.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.45-53
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• 2014

In this study, we analyzed the next generation ITS (C-ITS) technology trends, focusing on the national and international C-ITS projects. Based on the promotion practices of developed countries, we pointed out the lack of linkages with the existing ITS infrastructure. As a way to overcome this problem, we proposed the three-direction to enable the existing ITS infrastructure corresponding to the C-ITS. First one is developing a technique to improve the performance of the existing ITS infrastructure and automate the performance management (Performance-enhanced ITS). Second, developing active sensors or fusion sensor which along with V2X communication technology implement of an active safety driving support system (Safety-enhanced ITS). Third, we need to develop a technology that generate the new advanced traffic data by integrating the collected data from existing ITS infrastructure and nomadic device (Cloud-ITS). By improving the function of the existing ITS infrastructure for adaptation to the new V2X communication environment, we enhanced the efficiency of maintenance performance and would maximize the benefit of the introduction of C-ITS.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.3
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• pp.7-17
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• 2017

Loan consultants assist clients with loan application processing and loan decisions. Their duties may include contacting people to ask if they want a loan, meeting with loan applicants and explaining different loan options. We studied the efficiency of service quality of loan consultants contracted to a bank in Korea. They do not work as a team, but do work independently. Since he/she is not an employee of the bank, the consultant is paid solely in proportion to how much he/she sell loans. In this study, a consultant is considered as a decision making unit (DMU) in the DEA (Data Envelopment Analysis) model. We use a principal component analysis-data envelopment analysis (PCA-DEA) model integrated with Shannon's Entropy to evaluate quality efficiency of the consultants. We adopt a three-stage process to calculate the efficiency of service quality of the consultants. In the first stage, we use PCA to obtain 6 synthetic indicators, including 4 input indicators and 2 output indicators, from survey results in which questionnaire items are constructed on the basis of SERVQUAL model. In the second stage, 3 DEA models allowing negative values are used to calculate the relative efficiency of each DMU. In the third stage, the weight of each result is calculated on the basis of Shannon's Entropy theory, and then we generate a comprehensive efficiency score using it. An example illustrates the proposed process of evaluating the relative quality efficiency of the loan consultants and how to use the efficiency to improve the service quality of the consultants.

• Korean Journal of Clinical Pharmacy
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• v.28 no.2
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• pp.107-116
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• 2018

Objective: This study analyzed the national claims data of veterans to generate scientific evidence of the trends and appropriateness of their drug utilization in an outpatient setting. Methods: The claims data were provided by the Health Insurance Review & Assessment (HIRA). Through sampling and matching data, we selected two comparable groups; Veterans vs. National Health Insurance (NHI) patients and Veterans vs. Medical Aid (MAID) patients. Drug use and costs were compared between groups by using multivariate gamma regression models to account for the skewed distribution, and therapeutic duplication was analyzed by using multivariate logistic regression models. Results: In equivalent conditions, veteran patients made fewer visits to medical institutions (0.88 vs. 1), had 1.86 times more drug use, and paid 1.4 times more drug costs than NHI patients (p<0.05); similarly, veteran patients made fewer visits to medical institutions (0.96 vs. 1), had 1.11 times more drug use, and paid 0.95 times less drug costs than MAID patients (p<0.05). The risk of therapeutic duplication was 1.7 times higher (OR=1.657) in veteran patients than in NHI patients and 1.3 times higher (OR=1.311) than in MAID patients (p<0.0001). Conclusion: Similar patterns of drug use were found in veteran patients and MAID patients. There were greater concerns about the drug use behavior in veteran patients, with longer prescribing days and a higher rate of therapeutic duplication, than in MAID patients. Efforts should be made to measure if any inefficiency exists in veterans' drug use behavior.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.10
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• pp.1175-1184
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• 2008

Delay-sum back projection(DSBP) algorithm and the time reversal algorithm based on the finite-difference time-domain method are compared. The two algorithms, which operate in the time domain, can process the ultra-wideband (UWB) radar data to generate images that are close to the original location and shape of the target. For the experiment, the UWB radar consists of a network analyzer, a resistive V dipole antenna, a scanner, and a control computer. The radar aperture is synthesized by linearly scanning the antenna. A calibration procedure is applied to the measured data to remove signal distortion and clutter. The two algorithms are applied to the same data on the same platform. It is shown that the DSBP algorithm produces better images but takes longer time to produce the images than the FDTD-TR algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.285-287
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• 2017

Currently, the world of data communication is not simply communication between server and user in a wired way, but using wireless environment, various devices communicate with each other in a wider and diverse environment to generate a large amount of data. In this environment, IoT is now located deep in our lives, and IoT technologies are used in many tasks, but the data used in IoT is exposed without sufficient protection from malicious behavior. Most of these devices do not have enough computing power to cope with malicious attacks. In this paper, we aim to make all devices that have sufficient computing power and safety from simple sensors to be able to have security according to the situation. The proposed technology is based on the importance of the device and computing power, and it is possible to select the encryption technology selectively and to improve security.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.142-149
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• 2007

A ubiquitous environment in construction should be developed integrating hardware and software systems. The objective of this paper is to study the feasibility of applying the RFID technology to the concrete pour process, and improve the effectiveness of data exchange A pilot system of u-CPS (Ubiquitous Concrete Pour System) has been developed to test the feasibility. The pilot can automatically generate the data for concrete pour work such as departure time, arrival time, concrete pour time. Construction managers can keep track of the progress of concrete pour work using the information. A case study was done for a building construction using the pilot system, the result of which demonstrated that the RFID-base system can help improve the effectiveness of data communication during the concrete pour process.