• Journal of Korean Society of Disaster and Security
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• v.12 no.2
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• pp.73-82
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, the flood damage on riverside social infrastructures was extended so that there has been a threat of overflow. Therefore, a rapid prediction of potential flooding in riverside social infrastructure is necessary for administrators. However, most current flood forecasting models including hydraulic model have limitations which are the high accuracy of numerical results but longer simulation time. To alleviate such limitation, data driven models using artificial neural network have been widely used. However, there is a limitation that the existing models can not consider the time-series parameters. In this study the water surface elevation of the Hangang River bridge was predicted using the NARX model considering the time-series parameter. And the results of the ANN and RNN models are compared with the NARX model to determine the suitability of NARX model. Using the 10-year hydrological data from 2009 to 2018, 70% of the hydrological data were used for learning and 15% was used for testing and evaluation respectively. As a result of predicting the water surface elevation after 3 hours from the Hangang River bridge in 2018, the ANN, RNN and NARX models for RMSE were 0.20 m, 0.11 m, and 0.09 m, respectively, and 0.12 m, 0.06 m, and 0.05 m for MAE, and 1.56 m, 0.55 m and 0.10 m for peak errors respectively. By analyzing the error of the prediction results considering the time-series parameters, the NARX model is most suitable for predicting water surface elevation. This is because the NARX model can learn the trend of the time series data and also can derive the accurate prediction value even in the high water surface elevation prediction by using the hyperbolic tangent and Rectified Linear Unit function as an activation function. However, the NARX model has a limit to generate a vanishing gradient as the sequence length becomes longer. In the future, the accuracy of the water surface elevation prediction will be examined by using the LSTM model.

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.111-120
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• 2010

Looking at the application examples related to RFID systems around the world, it is easy to find that RFID systems are introduced in various industries, such as retail and consumer goods sectors, financial and security sectors, automotive and transport sector, leisure and sports sector, logistics, and health-related fields. This is because they can get their operational efficiency and competitiveness by means of product's visibility and transparency of information through RFID systems. However, it is required that evaluation of effectiveness on introducing RFID systems should be performed to strengthen construction willingness of RFID systems before actual introduction of the RFID systems in the process. This activity affects to introduction of RFID systems in industry-wide and then, will be able to create a synergy effect such as national industrial competitiveness improvement. The purpose of this study is to offer rational method on effectiveness analysis before and after RFID based process. Accordingly, the proposed Choquet fuzzy integral-based model will be allowed rational analysis by integrating quantitative and qualitative analysis. Through the effectiveness analysis of C company's RFID based process using the proposed evaluation model, we could identify that RFID-based logistics process was more effective than existing process.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.257-263
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• 2011

Conventional middleware is software providing services between clients and servers efficiently, but it is not applicable to RFID systems because of low consistency due to the absence of context awareness function, and problems in the management of meaning, security system, etc. Accordingly, we need a quality selection process and a quality evaluation method for selecting RFID middleware based on new criteria. This Paper proposed a new selection process based on international standard ISO/IEC 14598, and extracted and selected optimal quality factors through the proposed process. The selected quality factors were mapped to the quality characteristics of standard quality model ISO/IEC 9126, and to quality factors of RFID middleware of SUN, Microsoft, EPCglobal, IBM, etc. The results of these works showed that the quality factors extracted and selected through the proposed process were fair and adequate for evaluating the quality of RFID middleware.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.89-95
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• 2016

In this paper, we propose a locker system that can remotely control and manage locker. The main features of the proposed system are follows. First, connect the locker with server and then open the locker after passing through the certification process in server. Second, locker manager can more systematically manage a locker by using locker management system based on smart phone. Third, provide an instant locker for temporary using lockers to increase the ease of use. Fourth, unlike traditional analog locker, can support better security by using authentication process and log data. Performance evaluation is performed via simulation by making the dummy model. The results of performance evaluation show the proposed system can support efficiently the locker management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.408-420
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• 2010

On a Mobile Ad hoc NETwork(MANET), it is difficult to detect and prevent misbehaviors nodes existing between end nodes, as communication between remote nodes is made through multiple hop routes due to lack of a fixed networked structure. Therefore, to maintain MANET's performance and security, a technique to identify misbehaving middle nodes and nodes that are compromise by such nodes is required. However, previously proposed techniques assumed that nodes comprising MANET are in a friendly and cooperative relationship, and suggested only methods to identify misbehaving nodes. When these methods are applied to a larger-scale MANET, large overhead is induced. As such, this paper suggests a system model called Secure Cluster-based MANET(SecCBM) to provide secure communication between components aperANET and to ensure eed. As such, this pand managems suapemisbehavior nodes. SecCBM consists apetwo stages. The first is the preventis pstage, whereemisbehavior nodes are identified when rANET is comprised by using a cluster-based hierarchical control structure through dynamic authentication. The second is the post-preventis pstage, whereemisbehavior nodes created during the course apecommunication amongst nodes comprising the network are dh, thed by using FC and MN tables. Through this, MANET's communication safety and efficiency were improved and the proposed method was confirmed to be suitable for MANET through simulation performance evaluation.

• Korean Journal of Social Welfare
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• v.37
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• pp.271-306
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• 1999

This study aimed to present a comprehensive case management model which might be helpful for social workers in community social welfare agencies who works with North Korean refugees for their psychosocial adjustment in South Korea. After being constructed, the model was put into practice upon North Korean refugees. This article described the whole process of model construction and its application. Detail steps taken in this research include: (a) The researcher had 20 unstructured individual interviews with 11 North Korean refugees in order to identify psychosocial problems that need social workers' intervention; (b) Based upon the problems identified through interviews and previous literature review, program components were identified and sorted out into two phases, one of which is therapeutic phase, the other is case management phase; (c) By interlocking the two phases, the researcher proposed a comprehensive case management model whereby North Korean refugees can get psychosocial services as well as linkage services in an interactive fashion; (d) The utility of the proposed model was examined by using a couple of North Korean refugees who initially showed complicated psycho-social-economic problems. The therapeutic phase employed a cognitive-behavioral approach. The case management phase consists of: assessment and diagnosis; service planning and resource identification; linking of clients to needed services; monitoring of service delivery; and evaluation. Although the program could not go through with because of the limited contacts with North Korean refugees for security reasons, the program was turned out to be very useful in helping North Korean refugees' settling-down in South Korea. Implications for the application of the proposed model was discussed along with limitations of this study.

• The Journal of the Convergence on Culture Technology
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• v.3 no.2
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• pp.49-54
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• 2017

In Korea, partial self-driving feature is added on Genesis G80, Tivoli 2017, and others, and full implementation is under evaluation. Tesla already completed test for full self-driving car, Tesla Model 'X'. Further adoption of self-driving car in market will bring benefits to the elderly and disabled, meanwhile traffic accident will be decreased. However, related regulations for traffic accident with autonomous car including ethical responsibility is not fully established yet. In addition, security and privacy issue of self-driving cars should be improved as well. In this paper, domestic researches and analysis status on autonomous car will be summarized, and proper activation model will be proposed for the previously described issues.

• Korean Journal of Childcare and Education
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• v.3 no.2
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• pp.123-146
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• 2007

This study has attempted to suggest an assistant model for systematic child care accreditation. This has been carried out from the current consciousness of such needs for child care accreditation as large regional disparity in assistant level, no indication to definite contents and method of assistance, demand for assistant professionals with intensified capacity and requirement for the support of financial and human resources. Six stages of assistant process: the stage of establishment and management of preparation class, the stage of application for assistance and consultation, the stage of assistant meeting, the stage of workshop and observation to exemplary institutions, and the stage of practical application and evaluation of visiting assistance have been suggested. Particularly in order to improve the efficiency of assistance, organization of a committee of expert advisors in each area has been indicated. For the guideline of assistant management, operation of preparation class for accreditation, security of assistant committee members, provision of systematic training and assistant manual, development of supervision program and financial support have been suggested. This assistant manual will contribute to systematic and efficient conduct of assistance program of child care accreditation.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.518-518
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• 2016

Agriculture is the lifeblood of the economy in Ghana, employs about 42% of the population work force and accounts for 30% of the Gross Domestic Product (GDP). Corn (maize) is the major cereal crop grown as staple food under rain fed conditions, covers over 92% of the total agricultural area, and contributes 54% of the caloric intake. Issues of hunger and food insecurity for the entire nation are associated with corn scarcity and low production. The climate changes are expected to affect corn production in Ghana. This study evaluated variations of corn yields based on different climate conditions of rain-fed area in the Dangbe East District of Ghana. AquaCrop model has been used to simulate corn growing cycles in study area for this purpose. The main goal for this study was to predict yield of corn using selected climatic parameters from 1992 to 2013 using different climate scenarios. The Model was calibrated and validated using observed field data, and the simulated grain yields matched well with observed values for the season under production giving an R squared (R2)of 0.93 and Nash-Sutcliff Error(NSE) of 0.21. Study results showed that rainfall reduction in the range of -5% to -20% would reduce the yield from 1.315ton/ha to 0.421ton/ha (-21. 3%) whereas increasing temperature from 1% to 7% would result in the maximum yield reduction of -20.6% (1.315 to 1.09 ton/ha.). On the other hand, increasing rainfall from 5-20% resulted in yield increment of 68% (1.315-2.209 ton/ha) and decreasing temperature produce 7% increase in yield ( 1.315 to 1.401ton/ha). These results provide useful information to adopt strategies by the Government of Ghana and farmers for improving national food security under climate change.

• Smart Media Journal
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• v.12 no.7
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• pp.59-67
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• 2023

Recently, research on behavior analysis tracking human posture and movement has been actively conducted. In particular, OpenPose, an open-source software developed by CMU in 2017, is a representative method for estimating human appearance and behavior. OpenPose can detect and estimate various body parts of a person, such as height, face, and hands in real-time, making it applicable to various fields such as smart healthcare, exercise training, security systems, and medical fields. In this paper, we propose a method for classifying four exercise movements - Squat, Walk, Wave, and Fall-down - which are most commonly performed by users in the gym, using OpenPose-based deep learning models, DNN and CNN. The training data is collected by capturing the user's movements through recorded videos and real-time camera captures. The collected dataset undergoes preprocessing using OpenPose. The preprocessed dataset is then used to train the proposed DNN and CNN models for exercise movement classification. The performance errors of the proposed models are evaluated using MSE, RMSE, and MAE. The performance evaluation results showed that the proposed DNN model outperformed the proposed CNN model.