• International journal of advanced smart convergence
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• v.6 no.1
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• pp.82-88
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• 2017

Emergency lights and exit signs are an indispensable part of safety precautions for effective evacuation in case of emergency in public buildings. These emergency sign indicates safe escape routes and emergency doors, using an internationally recognizable sign. However visibility of those signs drops drastically in case of emergency situations like fire smoke, etc. and loss of visibility causes serious problems for safety evacuation. This paper propose a novel emergency light and exit sign built-in with Bluetooth Low Energy (BLE) Beacon to assist the emergency self-guiding evacuation using devices for crisis and emergency management to avoid panic condition inside the buildings. In this approach, the emergency light and exit sign with the BLE beacons deployed in the indoor environments and the smart devices detect their indoor positions, direction to move, and next exit sign position from beacon messages and interact with map server in the Internet / Intranet over the available LTE and/or Wi-Fi network connectivity. The map server generate an optimal emergency exit path according to the nearest emergency exit based on a novel graph generation method for less route computation for each smart device. All emergency exit path data interfaces among three system components, the emergency exit signs, map server, and smart devices, have been defined for modular implementation of our emergency evacuation system. The proposed exit sign experimental system has been deployed and evaluated in real-time building environment thoroughly and gives a good evidence that the modular design of the proposed exit sign system and a novel approach to compute emergency exit path route based on the BLE beacon message, map server, and smart devices is competitive and viable.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.213-217
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• 2015

Seoul has 25 areas of City Hall, the ward office has been operating theater at least 1 in maximum 4-5 locations to various sized places. The purpose of theater has been used for a variety of purposes to typical performances of Drama and Musicals, School play, Lecture. This points to a Variety of ideas for use, when replacing an exsting halogen luminaires, appropriate LED luminaires, Learn more if there is any advantage in terms of the energy saving part. it will be applied to the value for the energy saving to ward office hall of the actual targets. In case replacement in existing halogen luminaires to LED luminaires, to energy savings of about 80% appear around. Get the advantages of the various functional properties a device chip of the LED itself, Forward will be referred to as easy to replace the halogen luminaires and LED luminaires.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.2
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• pp.86-92
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• 2007

This paper presents the development of fire-fighting and rescue robot for Outdoor Environment. In the procedure of this development, we follow Target Oriented Design (TOD) which is recognized as the systematic methodology to design a system by specifying the target clearly. For some real fire fighting tasks (e.g. tasks in shopping street and a market), narrow road make it difficult for existing fire engine to access the firing place. On the other hand, for dangerous tasks (e.g. gasoline station and a storehouse) the explosive materials make it impossible for fire-fighters to access the firing place. Moreover, the smoke and the high-temperature caused by fire make fire fighting difficult. In this situation, the solution is to develop the fire-fighting and rescue robot. TOD is performed firstly by analyzing the environment properties of fro place and the demanded tasks and the fire-fighting and rescue robot is manufactured. For safety, the fire fighting robot should be controlled by remote operation to keep the operator away from the fire, and the control system is divided into three parts: the robot controllers, controller for remote operating device and wireless communication system. We have selected and developed appropriate hardware and software for each part of control system with considering TOD. As a result, the fire-fighting robot functions correctly and the performance and usefulness of our control architecture is validated by successfully performing some fire-fighting tasks.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.246.1-246.1
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• 2014

Over the past several years, colloidal core/shell type quantum dots lighting-emitting diodes (QDLEDs) have been extensively studied and developed for the future of optoelectronic applications. In the work, we fabricate an inverted CdSe/ZnS quantum dot (QD) based light-emitting diodes (QDLED). In order to reduce work function of indium tin oxide (ITO) electrode for inverted structure, a very thin (<10 nm) polyethylenimine ethoxylated (PEIE) is used as surface modifier[1] instead of conventional metal oxide electron injection layer. The PEIE layer substantially reduces the work function of ITO electrodes which is estimated to be 3.08 eV by ultraviolet photoemission spectroscopy (UPS). From transmission electron microscopy (TEM) study, CdSe/ZnS QDs are uniformly distributed and formed by a monolayer on PEIE layer. In this inverted QDLEDs, blend of poly (9,9-di-n-octyl-fluorene-alt-benzothiadiazolo) and poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] are used as hole transporting layer (HTL) to improve hole transporting property. At the operating voltage of 8 V, the QDLED device emitted spectrally orange color lights with high luminance up to 2450 cd/m2, and showed current efficacy of 0.6 cd/A, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.432.2-432.2
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• 2014

Recently, colloidal core/shell type quantum dots lighting-emitting diodes (QDLEDs) have been extensively studied and developed for the future of optoelectronic applications. In the work, we fabricate an inverted CdSe/ZnS quantum dot (QD) based light-emitting diodes (QDLED)[1]. In order to reduce work function of indium tin oxide (ITO) electrode for inverted structure, a very thin (<10 nm) polyethylenimine ethoxylated (PEIE) is used as surface modifier[2] instead of conventional metal oxide electron injection layer. The PEIE layer substantially reduces the work function of ITO electrodes which is estimated to be 3.08 eV by ultraviolet photoemission spectroscopy (UPS). From transmission electron microscopy (TEM) study, CdSe/ZnS QDs are uniformly distributed and formed by a monolayer on PEIE layer. In this inverted QD LED, two kinds of hybrid organic materials, [poly (9,9-di-n-octyl-fluorene-alt-benzothiadiazolo)(F8BT) + poly(N,N'-bis (4-butylphenyl)-N,N'-bis(phenyl)benzidine (poly-TPD)] and [4,4'-N,N'-dicarbazole-biphenyl (CBP) + poly-TPD], were adopted as hole transport layer having high highest occupied molecular orbital (HOMO) level for improving hole transport ability. At a low-operating voltage of 8 V, the device emits orange and red spectral radiation with high brightness up to 2450 and 1420 cd/m2, and luminance efficacy of 1.4 cd/A and 0.89 cd/A, respectively, at 7 V applied bias. Also, the carrier transport mechanisms for the QD LEDs are described by using several models to fit the experimental I-V data.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.242-250
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• 2010

Recently, the long-term care insurance for the elderly was carried out according to the elderly is increased rapidly and the formation of sympathy that a nation and society try commonly to share health and welfare promotion of the elderly. The purpose of this study is to analyze the present status of nursing home after that the long-term care insurance is enforced in chungcheongbuk-do and to utilize as basic data. The study limited its survey to those facilities that refer to the Ministry of Health and Welfare data, that had the capacity of more than 50 people. The result are as followings. Firstly, most of the nursing home were located on the outskirts of the city. But it must be constructed in the city center if the recent deinstitutionalization trend is reflected. Secondly, notwithstanding the provisions of the Elderly Welfare Law, if the Livability and amenity are considered, the plan of a single or a twin room is needed. The ondol(溫突) system bedroom for the safety of the elderly had to be planned and for the color planning of a bedroom, a heating, the furniture, the form of a door, corridors, etc. should be partly improved. The fastener in which it is appropriate for the main exit, a stair, an elevator, the lighting device, and etc. is needed and the installation of a wandering path for the dementia patient and etc. is required. Thirdly, most of the dining room arranged on the first floor but it is not nearly used and it used for employee or the other use. Therefore, we have to consider the system in which it can deliver the meal to a bedroom. If the smell of the elderly and etc. is considered, the sufficient height of the floor should be reflected for the ventilation equipment. Lastly, The improvement of the existing law are required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.329-332
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• 2012

LEDs are using widely in a field of illumination, LCD LED backlight, mobile signals because they have several merits, such as low power consumption, long lifetime, high brightness, fast response, environment friendly. To achieve high performance LEDs, one needs to enhance output power, reduce operation voltage, and improve device reliability. In this paper, we have proposed that the optimum design and specialized process could improve the performance of LED chip. It was showed an output power of 7cd and input supplied voltage of 3.2V by the insertion technique of current blocking layer. In this paper, GaN-based LED chip which is built on the sapphire epi-wafer by selective MOCVD were designed and developed. After that, their performances were measured. It showed the output power of 7cd more than conventional GaN-based chip. It will be used the lighting source of a medical equipment and LCD LED TV with GaN-based LED chip.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.235-240
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• 2017

Recently, Internet of things have been applied to various fields and are becoming common in our everyday life. Everything in our daily lives is networked, interacting with each other and giving us more useful effects. In this paper, we implemented an algorithm that can illuminate the LED lighting to the authorized person 's place in the network environment connected with the authentication device only once with the user authentication. User authentication in one building User authenticated through a single user search for the location of the user's lab stored in the database using the certified information and LED lights up to the lab where the user works. Through this, unnecessary energy is generated because people do not pass frequently.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.27-33
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• 2013

To ensure proper functioning of electrical and mechanical systems, cooling devices are of great importance. A heat sink is the most common cooling device used in many industries such as the semiconductor, electronic instrument, LED lighting, and automotive industries. To design an optimal heat sink, the required surface area for heat radiation should be calculated based on an accurate expectation of the heat flow rate in the target environment. In this study, the convective heat flow characteristics were numerically investigated for a vertically installed typical heat sink and a horizontally installed one in free convection using ANSYS CFX. Comparative experiments were carried out to reveal the quantitative effect of the installation direction on the cooling performance. Moreover, the result was analyzed using the dimensionless correlation with the Nusselt number and Rayleigh number and compared with well-known theories. Finally, it was observed that the cooling performance of the vertically installed heat sink is approximately 10~15% better than that of the one in natural convection.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.3
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• pp.106-111
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• 2018

Halide perovskite nanocrystals have become attractive for LED applications due to their high color purity and excellent luminescent properties. $CsPbX_3$ (X = I, Br, and Cl) nanocrystals were synthesized by hot-injection method and the emission wavelength was controlled by changing the composition of halide ion. Green- and red-emitting films were fabricated using a polymer binder. The outstanding optical properties of the synthesized nanocrystals and fabricated films were confirmed. The wLED designed by green- and red-emitting perovskite nanocrystal films on blue InGaN LED was characterized.