• 한국압력기기공학회 논문집
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• 제19권1호
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• pp.6-10
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• 2023

Only about 10% of selected equipment in nuclear power plants are monitored by wiring to address failures or problems caused by vibration. The purpose is primarily for preventive maintenance, not for predictive maintenance. This paper shows that vibration monitoring and diagnosis using Industrial 4.0 enables the complete predictive maintenance for all vibrating equipments in nuclear power plants with the convergence of internet of things; wireless technology, big data through periodic collection and artificial intelligence. Predictive maintenance using wireless technology is possible in all areas of nuclear power plants and in all systems, but it should satisfy regulatory guides on electromagnetic interference and cyber security.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.597-600
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• 2003

Wireless Internet access shows an early-stage market that is entering a period of strong and sustained growth., reaching almost $40 billion in combined related equipment services by 2008 with equipment and services of nearly equal proportion. This explosive development is possible due to the continued growth of two of the most successful markets in history, the internet and mobile telephony. The number of global wireless internet users will incense from approximately 1.9million in 2001 to 1.3billion by 2006. Technological changes are the main factor in the emergence of what is being called the fourth generation of mobile communications.

• 기술혁신연구
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• 제18권2호
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• pp.253-288
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• 2010

본 연구는 기업의 지속적 생존과 성장이 변화하는 환경에 대응할 수 있는 지속적인 제품혁신에 있음에 초점을 두고, 산업 진화과정이 기업의 제품혁신 유형에 어떤 영향을 미치고 있는지와 인지, 기회구현, 변형의 세 가지 동태적 역량이 제품혁신에 미치는 영향을 분석하였다. 연구분석을 위해 1999년부터 2008년까지 산업의 도입기부터 성장기, 성숙기, 쇠퇴기를 모두 경험함으로써 종단적 분석에 적합한 한국 무선인터넷 산업의 7개 상장 기업에 대한 인터뷰와 문헌조사를 통한 사례연구를 수행하였다. 본 연구의 분석을 통하여 발견된 주요 결과는 다음과 같다. 첫째, 산업의 성장률이 둔화되는 성숙기 또는 쇠퇴기에는 제품혁신의 경로종속성은 낮아지고, 산업진화 과정의 외생적 변수가 중요해진다. 둘째, 기업의 인지활동은 상위 수준의 전략에 영향을 많이 받으며, 인지활동 범위와 제품혁신의 유형과는 밀접한 관계가 있다. 따라서 지속적인 성장을 위해서는 다양한 영역의 인지활동이 필요하다. 셋째, 기회구현역량은 제품혁신의 성공가능성에 영향을 미치며, 궁극적으로 기업의 재무적 성과에 기여하게 된다. 특히 경로종속성이 높은 제품혁신을 선택했을 때 높은 성과를 얻을 수 있으며, 적절한 비즈니스 모델의 개발과 필요한 자원 및 역량의 조달이 병행될 때 가능성은 높아진다. 넷째, 변형역량이 강한 기업이 그렇지 못한 기업에 비해 기존 역량을 활용할 수 있는 점진적 유형의 제품혁신을 선택할 확률이 크다. 결론적으로 기업이 성공적인 제품혁신을 추진하기 위해서는 산업 진화과정의 고려와 함께 균형적인 동태적 역량의 개발이 반드시 필요하며 이것이 기업의 지속적인 생존과 성장에 중요한 영향을 미친다고 할 수 있다.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.9-16
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• 2017

The performance test is conducted for the purpose of determining the accurate thermal performance of the power generation facility or deriving the factors of thermal efficiency degradation. Compared to the acquisition method of power plant thermal performance test data by compensating cable or transmission cable, performance test using wireless instrument can acquire digital data in order to shorten the period due to installation and demolition of instrument and enhance safety of workers and relatively accurate data can be acquired thereby improving work efficiency. Wireless instruments have already been introduced to the market a long time ago, and some of them are used in industry such as petrochemical industry. However, there is no example which has been conducted for performance test of power generation facilities. In order to apply power generation facilities, a reliable system capable of acquiring performance data smoothly without affecting the control system is required. The wireless measurement system can eliminate the measurement defects and errors such as the damage due to the movement of the connecting cable, the extension due to the extension of the shield wire, the contact failure at the contact point between the measuring sensor and the connecting wire, This method has the advantage of collecting relatively accurate performance test data.

• 디지털산업정보학회논문지
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• 제11권1호
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• pp.69-78
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• 2015

Internet of Things(IoT) is electronic devices and household appliances use wireless sensor network in environment of high speed wireless network and LTE mobile service. The combination of the development of Internet and wireless network led to development of new forms of service such as electronic devices and household appliances can connect to the Internet through various sensors and online servers such as a Home Network. Even though Internet of Things is useful, there are problems in Internet of Things. In environment of Internet of Things, information leakage could happens by illegal eavesdropping and spoofing. Also illegal devices of wireless communication interference can cause interfere in Internet of things service, physical damage and denial of service by modulation of data and sensor. In this thesis, it will analyze security threats and security vulnerability in environment of mobile services and smart household appliances, then it will suggest plan. To solve security issues, it is important that IT and RFID sensor related companies realize importance of security environment rather than focus on making profit. It is important to develop the standardized security model that applies to the Internet of Things by security-related packages, standard certification system and strong encrypted authentication.

• 디지털산업정보학회논문지
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• 제10권3호
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• pp.161-169
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• 2014

Wireless Ad Hoc Network is suitable for emergency situations such as and emergency, disaster recovery and war. That is, it has a characteristic that can build a network and use without help of any infrastructure. However, this characteristic is providing a cause of many security threats. In particular, routing attack is not applied the existing routing methods as it is and it is difficult to determine accurately whether nodes that participate in routing is malicious or not. The appropriate measure for this is necessary. In this paper, we propose a secure routing technique through a zone architecture-based node authentication in order to provide efficient routing between nodes. ZH node is elected for trust evaluation of the member nodes within each zone. The elected ZH node issues a certification of the member nodes and stores the information in ZMTT. The routing involvement of malicious nodes is blocked by limiting the transfer of data in the nodes which are not issued the certification. The superior performance of the proposed technique is confirmed through experiments.

• 한국정보통신학회논문지
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• 제19권2호
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• pp.272-278
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• 2015

본 논문은 ISM (Industry Science and Medical) 대역에서 동시 다발적으로 운용 가능성이 높은 무선 헤드셋 수신기 시스템과 WiFi (Wireless Fidelity) 시스템간의 간섭 영향을 분석하였다. WiFi는 IEEE (Institute of Electrical and Electronic Engineers ) 802.11b 규격을 바탕으로 하여 특성 및 파라미터를 적용하였으며, 분석방법으로는 최소결합 손실(MCL; Minimum Coupling Loss) 방법과 몬테카를로(MC; Monte Carlo) 방법을 사용하였다. MCL 방법을 통해서 무선 헤드셋의 수신기와 WiFi기기의 송신기 간의 보호이격거리를 도출하였으며, 통계적 분석을 바탕으로 한 MC 방법을 이용해서 5 %이하의 간섭 확률을 만족시켜 주기 위한 단일 간섭원에 따른 보호이격거리 도출 및 희생원의 셀 반경에 따른 허용 가능한 최대 간섭원 수를 도출하였다. 분석 결과는 ISM 대역에서 사용되고 있는 무선 헤드셋 시스템 및 기타 소출력 기기들의 공유방안으로 활용될 것으로 기대된다.

• 대한안전경영과학회지
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• 제15권3호
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• pp.143-150
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• 2013

A cell site lease is a legal agreement by which the owner of a building or a piece of land allows a wireless carrier to use part of it for a cell tower for a period of time in return for money. Wireless carriers spend significant money for cell site leases. This paper tries to find factors affecting cell site leases and management solutions to save lease costs. In other words, this research identifies any factor influencing cell site leases among age, gender, and geographical area in the first problem and determines management priorities using an importance-satisfaction model in the second problem. This paper can provide wireless carriers with effective decision making tools and a basis for negotiation of cell site leases, as they do not have enough bases for negotiation.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.109-116
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• 2014

In recent, ISM (Industrial Scientific Medical) band that is 2.4GHz band authorized free of charge is being widely used for smart phone, notebook computer, printer and portable multimedia devices. Accordingly, studies have been continuously conducted on the possibility of coexistence among nodes using ISM band. In particular, the interference of IEEE 802.11b based Wi-Fi device using overlapping channel during communication among IEEE 802.15.4 based wireless sensor nodes suitable for low-power, low-speed communication using ISM band causes serious network performance deterioration of wireless sensor networks. This paper examined a method of identifying channel status to avoid interference among wireless communication devices using IEEE 802.11b (Wi-Fi) and other ISM bands during communication among IEEE 802.15.4 based wireless sensor network nodes in ISM band. To identify channels occupied by Wi-Fi traffic, various studies are being conducted that use the RSSI (Received Signal Strength Indicator) value of interference signal obtained through ED (Energy Detection) feature that is one of IEEE 802.15.4 transmitter characteristics. This paper examines an algorithm that identifies the possibility of using more accurate channel by mixing utilization of interference signal and RSSI mean value of interference signal by wireless sensor network nodes. In addition, it verifies such algorithm by using OPNET Network verification simulator.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.23-24
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• 2009

In dangerous Industry fields (eg. construction, shipbuilding, the mining industry, and so on) many employees have lost their life due to risky environment, so that costs of social and Industry have been increased. To solve this problem, we Implement u-helmet using temperature, humidity, illumination sensors and monitoring GUI system.