• 전기학회논문지
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• 제61권1호
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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.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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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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• 제6권4호
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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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• 제19권1호
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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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• 제13권1호
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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.

• 한국도로학회논문집
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• 제19권4호
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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.

• 정보처리학회논문지D
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• 제11D권3호
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• pp.731-740
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• 2004

본 논문에서는 상거래에 참여한 구매자와 판매자가 협상을 통하여 서로의 이익을 보장하면서 합의를 도출 할 수 있는 협상 에이전트 시스템을 제안하였다. 제안 시스템은 기존의 협상 에이전트 시스템에 기계 학습을 적용함으로써, 학습 에이전트의 도입이 협상의 효율성에 어떤 영향을 미치는지 고찰하고자 하였다. 구매자 및 판매자 에이전트는 상품의 다중 속성을 고려하여 협상을 수행하며, 구매자와 판매자의 이익은 Multi-Attribute Utility Theory를 이용하여 표현하였다. 본 연구에서 제시된 학습 가능한 협상 에이전트는 Faratin이 제안한 협상 시스템의 제안 생성(counter offer) 과정에 인공신경망을 통한 점진적 학습 기업을 추가함으로써 협상의 효율성을 증가시키는데 목적이 있다. 점진적 학습기법을 이용한 협상 에이전트 시스템의 경우, 동일한 협상 조건 하에서 상대방 제안과의 유사도(similarity)를 바탕으로 제안을 생성하는 기존의 다른 협상 에이전트 시스템과 비교하였을 때 좋은 협상 결과를 보여 주었으며, 협상 수행시간에 있어서는 매우 빠른 성능을 보여주었다. 따라서 협상 결과 및 협상 수행 시간을 동시에 고려하였을 때 기존의 협상 시스템에 비하여 효율적인 협상 능력을 보여 주었다.

• 여성건강간호학회지
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• 제17권5호
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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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• 제22권3호
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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.

• 공학교육연구
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• 제2권1호
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• pp.10-16
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• 1999

본 논문에서는 인터넷을 이용한 디지탈 논리회로 설계 및 모의실험실습을 위한 교육용 소프트웨어 패키지(DVLab)를 개발하였다. 개발된 패키지는 디지탈 조합/순차회로는 물론 마이크로콘트롤러 응용회로까지 설계하고 시뮬레이션할 수 있는 모듈, 브레드보드 시뮬레이터 모듈, 실험항목별 이론 강의를 위한 모듈, 보고서 작성 및 보고서 자동검사 모듈 등을 포함하고 있다. 개발된 모든 모듈들은 독립적인 응용 프로그램으로 뿐만 아니라 인터넷을 이용한 사용이 가능하며, 특히 시뮬레이터 모듈의 경우 실시간 클럭 제공, 설계회로도 상에서 직접 소자의 출력값 확인, 논리값 변화 기록 기능, 설계회로 복사 방지 기능, 다양한 논리회로 소자뿐만 아니라 LED, buzzer등과 같은 시각적, 청각적 소자 제공 등의 특징을 가진다. 또한 개발된 교육용 패키지를 이용한 디지탈 논리회로 실험실습 과목의 학습 모형을 제시하였다.