• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.41-49
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• 2012

This paper describes the operation mode development for the grid-tied PMSG(permanent magnet synchronous generator) wind power system combined with a battery energy storage. The development of operation modes was carried out through simulations with PSCAD/EMTDC software and experiments with a 10kW hardware prototype. The detailed simulation models for PMSG wind power system and battery energy storage were developed using user-defined models programed with C-code. A 10kW hardware simulator was built and tested in connection with the local load and the utility power. The simulation and experimental results confirm that the grid-tied PMSG wind power system combined with battery energy storage can supply highly reliable power to the local load in various operation modes.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.946-948
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• 2003

This paper describes the development of an INS (Inertial Navigation System) integrated positioning system, which can monitor and track the firefighter's position for assisting effective fire-fighting activity and rescue services. The INS consists of highly accurate three-axis gyro sensor and three-axis accelerometer. By integrating an INS to positioning system, it is also possible to obtain the information of firefighter's physical state (e.g. standing, collapse and crouch) of posture including velocity. Consequently, this research would obviously make a contribution to effective rescue activities and safety of firefighters. Besides, this paper presents results from field tests conducted at Tokyo University demonstrating its viability and utility. We also summarize the overall system requirements and architecture, and describe the hardware and software used in the prototype system in detail.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.284-291
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• 2018

As environmental pollution has become worse green technologies to replace or reduce consumption of fossil fuel get spotlight from government, industry and academia globally. It is reported that 40% of carbon dioxide emission is caused by electricity power generation. And 37% of end user electricity power is used by residential costumer in US. Smart Grid is considered as one of promising technology to alleviate severe environmental problem. In residential environment, Home Energy Management System (HEMS) can play a key role for green smart home. The HEMS can give several benefits like aslowering electric utility bill, improvement of efficiency of electric power consumption and integration of generator using renewable energy resources. However just limited functions of HEMS can be used for residential customer in real life because of lack of smart function in home appliances and optimal managing software for HEMS. This study provides comprehensive analysis for Home Energy Management System for residential customer. Simple HEMS system with real products on the market are explained and limitation of current HEMS are also discussed.

• Journal of information and communication convergence engineering
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• v.19 no.1
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• pp.29-35
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• 2021

While the population of pet dogs and pet-related markets are increasing, there is no convenient and reliable tool for pet health monitoring for pet owners/caregivers. In this paper, we propose a mobile platform-based pre-diagnosis system that pet owners can use for pre-diagnosis and obtaining information on coping strategies based on their observations of the pet dog's abnormal behavior. The proposed system constructs symptom-disease association databases for 100 frequently observed diseases under veterinarian guidance. Then, we apply the possibilistic fuzzy C-means algorithm to form the "probable disease" set and the "doubtable disease" set from the database. In the experiment, we found that the proposed system found almost all diseases correctly, with an average of 4.5 input symptoms and outputs 1.5 probable and one doubtable disease on average. The utility of this system is to alert the owner's attention to the pet dog's abnormal behavior and obtain an appropriate coping strategy before consult a veterinarian.

• International journal of advanced smart convergence
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• v.13 no.1
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• pp.1-11
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• 2024

Cognitive small cell networks, consisting of macro-cells and small cells, are foreseen as a promising candidate solution to address 5G spectrum scarcity. Recently, many technological issues (such as spectrum sensing, spectrum sharing) related to cognitive small cell networks have been studied, but the common control channel (CCC) establishment problem has been ignored. CCC is an indispensable medium for control message exchange that could have a huge significant on transmitter-receiver handshake, channel access negotiation, topology change, and routing information updates, etc. Therefore, establishing CCC in cognitive small cell networks is a challenging problem. In this paper, we propose a potential game theory-based approach for CCC establishment in cognitive radio networks. We design a utility function and demonstrate that it is an exact potential game with a pure Nash equilibrium. To maintain the common control channel list (CCL), we develop a CCC update algorithm. The simulation results demonstrate that the proposed approach has good convergence. On the other hand, it exhibits good delay and overhead of all networks.

• International Journal of Highway Engineering
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• v.19 no.4
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• pp.45-52
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• 2017

PURPOSES : This study was initiated to estimate the utilities of usage attributes of BRT and Bimodal Trams using a conjoint analysis method in order to identify the important features pertaining to the use of BRT and Bimodal Trams. METHODS : For this purpose, important attributes and those level in the use of BRT and Bimodal Trams in the city of Sejong were identified. Next, a profile questionnaire pertaining to BRT and Bimodal Trams was designed for the conjoint analysis, and a survey was conducted in the city of Sejong. Using SPSS software, conjoint analysis was performed to identify the important attributes vis-$\acute{a}$-vis the use of BRT and Bimodal Trams in the city of Sejong. Finally, the utilities for individual attributes were calculated based on the models estimated by the conjoint analysis. RESULTS : The results of the conjoint analysis were used to identify the important attributes. With regard to the usage of BRT, users indicated that fare was the most important attribute with the highest utility. In the case of Bimodal Trams, the users indicated that the number of seats and internal environment were the most important attributes with the highest utilities. CONCLUSIONS : Based on the results of the conjoint analysis, the important attributes pertaining to the use of BRT and Bimodal Trams in the city of Sejong were identified. Our study indicates that BRT in the city of Sejong needs to be upgraded to improve the utilities of the important attributes. Currently, Bimodal Trams has not been introduced completely in the city of Sejong. However, in the future, when the introduction of Bimodal Trams is completed, the important attributes should be emphasized in order to improve the quality of its service.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.731-740
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• 2004

In this paper we propose a fast negotiation agent system that guarantees the reciprocity of the attendants in a bilateral negotiation on the e-commerce. The proposednegotiation agent system exploits the incremental learning method based on an artificial neural network in generating a counter-offer and is trained by the previous offer that has been rejected by the other party. During a negotiation, the software agents on behalf of a buyer and a seller negotiate each other by considering the multi-attributes of a product. The experimental results show that the proposed negotiation system achieves better agreements than other negotiation agent systems that are operated under the realistic and practical environment. Furthermore, the proposed system carries out negotiations about twenty times faster than the previous negotiation systems on the average.

• Women's Health Nursing
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• v.17 no.5
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• pp.439-446
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• 2011

Purpose: Early diagnosis is the primary method aimed at controlling breast cancer. The purpose of this study was to analyze some factors affecting the performance of mammography screening among women with a family history of breast cancer in Korea. Methods: This study applied a descriptive design method through structured self-report questionnaires. The Care Seeking Behavior Theory provided a theoretical framework for the study. Factors measured in this study represent demographic, clinical, and psychosocial variables including anxiety, barriers, utility, habits, perception, and facilitators. A total of 212 participants, of at least 20 years old, were sampled from April 8, 2010 to March 31, 2011. The data was analyzed by logistic regression method using the Statistical Package for the Social Science 18.0 software. Results: Of the 212 participants, 122 women (57.5%) went through mammography screening. The results of the analysis showed that (a) age (Odds Ratio [OR] =1.10, p<.001), (b) facilitating influences (OR=1.83, p=.008), (c) perception of mammography importance (OR=1.92, p=.011), (d) barriers to mammography (OR=0.60, p=.031), and (e) utility of mammography (OR=2.01, p=.050) significantly affect mammography screening. Conclusion: The results underscore the impact that psychosocial variables in obtaining mammography have on adherence to screening. Women with a family history of breast cancer should be given accurate information and recommendation about mammography by healthcare provider and a regular source of healthcare.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.442-453
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• 2021

Artificial intelligence (AI) will likely affect various fields of medicine. This article aims to explain the fundamental principles of clinical validation, device approval, and insurance coverage decisions of AI algorithms for medical diagnosis and prediction. Discrimination accuracy of AI algorithms is often evaluated with the Dice similarity coefficient, sensitivity, specificity, and traditional or free-response receiver operating characteristic curves. Calibration accuracy should also be assessed, especially for algorithms that provide probabilities to users. As current AI algorithms have limited generalizability to real-world practice, clinical validation of AI should put it to proper external testing and assisting roles. External testing could adopt diagnostic case-control or diagnostic cohort designs. A diagnostic case-control study evaluates the technical validity/accuracy of AI while the latter tests the clinical validity/accuracy of AI in samples representing target patients in real-world clinical scenarios. Ultimate clinical validation of AI requires evaluations of its impact on patient outcomes, referred to as clinical utility, and for which randomized clinical trials are ideal. Device approval of AI is typically granted with proof of technical validity/accuracy and thus does not intend to directly indicate if AI is beneficial for patient care or if it improves patient outcomes. Neither can it categorically address the issue of limited generalizability of AI. After achieving device approval, it is up to medical professionals to determine if the approved AI algorithms are beneficial for real-world patient care. Insurance coverage decisions generally require a demonstration of clinical utility that the use of AI has improved patient outcomes.

• Journal of Engineering Education Research
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• v.2 no.1
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• pp.10-16
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• 1999

In this paper, we developed the internet-based educational software package (DVLab) for design and virtual experiment of the digital logic circuits. The DVLab consists of the LogicSim module for design and simulation of digital combinational/sequantial logic circuits, micro-controller application circuits and the BreadBoard module for virtual experiment and the Theory module for lecture and the Report/ReportChecker module and some other utility modules. All developed modules can be run as application programs as well as applets in the Internet. The LogicSim and the BreadBoard support real time clock function, output verification function on the designed circuits, trace function of logic values, copy-protection function of designed circuits and provide various devices including logic gates, TTLs, LED, buzzer, and micro-controller. The educational model of digital logic circuit design and experiment using the DVLab is also presented in this paper.