• 한국통신학회논문지
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• 제40권2호
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• pp.390-396
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• 2015

무선인터넷과 이동통신 기술의 발달 및 스마트폰의 급속한 확산으로 인해 사용자의 현재 및 과거의 위치 정보를 사용하여 다양한 부가정보를 제공하는 위치기반 서비스에 대한 관심이 급증하고 있다. 위치기반 서비스의 본격적인 활성화를 위해서는 정확한 측위가 기본이 된다. GPS (Global Positioning System)와 WPS (Wi-Fi Positioing System)가 상용화 되면서 측위 기술에 일대 혁신을 가져왔으나 실내환경에서 많은 제약을 가졌고 스마트폰에 일반적으로 설치되는 관성센서 (IMU: Inertia Motion Unit)를 사용한 네비게이션 (Navigation)기술을 실내 환경에서 응용하는 시도도 일정부분 성과를 거두었다. LED 조명을 이용한 실내 측위는 LED 조명으로부터 특정 신호를 수신하여 해석을 하는 Li-Fi (Light Fidelity) 통신의 부가 서비스의 한 형태로 조명 받았으나, LED 조명으로부터 신호를 수신하기 위한 수신기를 갖추어야 하는 실제적인 문제가 있다. 본 논문에서는 부가 장비 없이 스마트폰의 이미지 센서만을 이용하여 LED 조명으로부터 신호를 수신하여 해석하는 방식을 제시하고 이를 실내 측위에 이용하는 응용 서비스 기술을 제안한다.

• 한국통신학회논문지
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• 제37C권10호
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• pp.901-908
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• 2012

미래의 지능형 공장 환경은 관리자가 M2M (Machine-to-Machine) 통신을 이용하여 원격으로 공장 안의 기기들의 동작 상태와 환경을 인지하고 관리하는 것을 목표로 하고 있다. 하지만, 공장 안에서 사용하는 통신 프로토콜인 WLAN (Wireless Local Area Network), ZigBee, Bluetooth 등은 동일한 ISM (Industrial Scientific Medical) 대역을 사용하기 때문에 상호 간섭이 발생하게 된다. 본 논문에서는 Fingerprinting 무선측위 기술을 이용하여 영역 기반으로 주파수를 할당하는 기법을 제안한다. 그리고 일반적인 기법이 가지고 있는 측위 성능의 문제점을 개선하기 위하여, k-NN (Nearest Neighbor) 알고리즘을 적용하고 또한 이를 기반으로 한 새로운 기법도 제안한다. 모의실험 결과를 통해 제안된 무선측위 알고리즘이 다른 기법들보다 측위 성능의 오차가 감소하였으며, 궁극적인 목표로 하고 있는 채널 간섭율 또한 향상되었기에 주파수의 간섭을 보다 효율적으로 관리할 수 있다는 결론을 얻었다. 아울러 지속적인 위치 추정을 통하여 공장 환경 내 안전도 보장할 수 있음을 확인하였다.

• 한국통신학회논문지
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• 제42권3호
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• pp.686-697
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• 2017

고령자들의 정신적/육체적 건강 유지를 위해 디지털 메디신 (Digitial Medicine)의 일환으로 일상에서의 운동 프로그램을 사용하는 시도가 다양하게 이루어지고 있다. 특히 웨이러블 기기에 부착된 센서를 활용한 운동 처방과 분석 방법은 IoT 기술을 헬스케어 분야에 적용시키는 대표적인 예로 제시된다. 본 연구에서는 현재 수원시 노인정신건강센터에서 운영하는 운동 프로그램에서 기존에 수기로 수집되고 작성되는 데이터 분석의 신뢰성을 개선하고 노인들의 운동 동기를 촉구하고자 스마트밴드와 BLE 스캐너 장치를 활용하여 IoT(Internet of Thing)기반 행동 인터벤션(intervention) 시스템을 구현한다. 실제 운동 처방과 운동 데이터 분석을 통해 행동 인터벤션 시스템을 테스트하여 데이터 수집과 분석의 무결성을 검증하고 시스템의 개발과 적용에 대한 일련의 과정을 제시한다.

• 수산경영론집
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• 제49권4호
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• pp.69-81
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• 2018

The fishing vessel buyback program, that is, the project of fishing vessel reduction is a complex challenge that needs to take into consideration for both fishing resource protection and industrial restructuring. By the way, the fishing vessel buyback program in Korea is still poorly fruitful and there are few applications for the project in the country. For example, the buyback program of this nation has some problems like uncertainly set goals, conflicts among targets, no flexibility in the program implementation, low participation in the project and lack in follow-up actions. To solve these problems, this study offers the following alternatives. First, it is setting up detailed targets for fishing vessel buyback. Those targets should be what can be actually driven under policy support, such as reduction in illegal fishing, decrease in an exact number of fishing vessels and decline in fishing capacity rather than what seem to be comprehensive such as protection of coastal or offshore fishery and industrial restructuring. Second, it is taking measures for the livelihood of those who would face disadvantages due to fishing vessel reduction. Those measures providing or supporting the re-education and re-employment of fishery workers and building up systems that help the workers transfer fishing to another job. Third, it is adopting the governance system that overcomes lacks in communications between the fishing vessel buyback program and improves the performance effectiveness of that program. Here, governance means that businesses and authorities concerned in the program interact and cooperate with one another in making and implementing policies related to the project of fishing vessel reduction and assessing the results of that project. Fourth, it is taking actions for fishery reorganization after the fishing vessel buyback program. Factors that can be considered as those actions include supporting fishery workers' cost of fishing vessel reduction, decreasing and modernizing fishing fleets and improving the quality of fishing equipment. In conclusion, the fishing vessel buyback program should be prepared with comprehensive actions or measures that can cope well with a variety of problems that may be arisen from it while keeping itself on the track of its original goals.

• 대한조선학회논문집
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• 제60권5호
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• pp.367-374
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• 2023

As the Fourth Industrial Revolution accelerating, countries worldwide are developing technologies to digitize and automate various industrial sectors. Building smart factories not only reduces costs through improved process productivity but also allows for preemptive identification and removal of risk factors through the practice of Health, Safety, and Environment (HSE) management, thereby reducing industrial accident risks. In this study, we visualized pressure, temperature, power, and wind speed data measured in real-time via a monitoring GUI, enabling field managers and workers to easily access related information. Through the work environment monitoring system developed in this study, it is possible to conduct economic analysis on per-unit basis, based on the digitization of production management elements and the tracking of required resources. By implementing HSE in shipyards, potential risk factors can be improved, and gas and electrical leaks can be identified, which are expected to reduce production costs.

• 한국CDE학회논문집
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• 제20권3호
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• pp.254-262
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• 2015

This study proposes an approach to Product Data Management (PDM) education for collaborative product data management, which can support collaborative product development process. This approach introduces social media and a PDM system into a framework for PDM education supported by consistent product development process and product data model. It has been applied to two PDM classes and the result shows that the social media in PDM education can support not only experiences of the collaborative product data management but also interactive and informal communications among instructors and participants using integrated social media with product data during courses.

• ETRI Journal
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• 제37권1호
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• pp.175-185
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• 2015

This paper presents a system-of-systems (SoS) approach to the formal modeling of a cyber-physical system (CPS) for simulation-based analysis. The approach is based on a convergence technology for modeling and simulation of a highly complex system in which SoS modeling methodology, hybrid systems modeling theory, and simulation interoperation technology are merged. The methodology maps each constituent system of a CPS to a disparate model of either continuous or discrete types. The theory employs two formalisms for modeling of the two model types with formal specification of interfaces between them. Finally, the technology adapts a simulation bus called DEVS BUS whose protocol synchronizes time and exchange messages between subsystems simulation. Benefits of the approach include reusability of simulation models and environments, and simulation-based analysis of subsystems of a CPS in an inter-relational manner.

• Communications for Statistical Applications and Methods
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• 제22권6호
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• pp.639-646
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• 2015

We propose simultaneous tests for mean and variance under the normality assumption. After formulating the null hypothesis and its alternative, we construct test statistics based on the individual p-values for the partial tests with combining functions and derive the null distributions for the combining functions. We then illustrate our procedure with industrial data and compare the efficiency among the combining functions with individual partial ones by obtaining empirical powers through a simulation study. A discussion then follows on the intersection-union test with a combining function and simultaneous confidence region as a simultaneous inference; in addition, we discuss weighted functions and applications to the statistical quality control. Finally we comment on nonparametric simultaneous tests.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.228-230
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• 2004

ZigBee Alliance is a network designed for low-cost and very low-power short-range wireless communications. The ZigBee Alliance is a consortium formed by several leading semiconductor and industrial manufactures, and end users. One of the tasks of this organization is the definition of the networking support and applications profiles that will use IEEE Std 802.15.4-compliant transceivers. In the case of IEEE Std 802.15.4, the ZigBee Alliance is an organization that has led the development of the upper layers, through the definition of application profiles. We have implemented ZigBee home control system, however we have not fully implemented. Because of the ZigBee is not perfectly standarded. We will have to implement according to ZigBee Specifications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.653-656
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• 2004

This paper outlines the three main fieldbus type standards: Foundation Fieldbus; WorldFIP; and the Profibus, each of which have great advantages over traditional instrumentation networking technology. The paper shows, using their specification, how they improve traditional control and data acquisition methods. By analysing the main robust, how the can be used to distribute data around the control system, provided increased diagnostic information, are easy to implement, fault confinement, and move simple control operations from the main controller to the local environment. This will help to segment industrial plants into zones which can control themselves. The main control will then be responsibility high-level control. and interzone communications.