• Fire Science and Engineering
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• v.33 no.6
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• pp.186-189
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• 2019

NFSC 202 stipulates that if a loudspeaker or wiring on one floor of a building is shorted because of fire, it should not interfere with the fire notification on the other floors. To address this problem, this study proposes an ultrasonic transmitter/receiver consisting of an ADC, HPF, and LPF in an emergency broadcasting system that can operate regardless of the volume level of the amplifier output loudspeaker capacity. After transmitting the transmission frequency at -12 dB (110 kHz), it is received at -18 dB by transmitting -12 dB in case of short circuit depending on the frequency characteristics. Typically, depending on the loudspeaker capacity, it is received from -24 dB to -66 dB. In case of disconnection, it exceeds -66 dB and no data are received. It is also possible to check the track status during fire or general broadcasting. Thus, it was confirmed that the system is suitable for NFSC 202 regulations. Furthermore, as the current system is replaced, the inspection or test criteria should be amended or revised.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.65-73
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• 2002

In this paper, we propose and verify an implementation method for a single-chip 2048 complex point FFT/IFFT in terms of sequential data processing. For the sequential processing of 2048 complex data, buffers to store the input data are necessary. Therefore, DRAM-like pipelined commutator architecture is used as a buffer. The proposed structure brings about the 60% chip size reduction compared with conventional approach by using this design method. The 16-point FFT is a basic building block of the entire FFT chip, and the 2048-point FFT consists of the cascaded blocks with five stages of radix-4 and one stage of radix-2. Since each stage requires rounding of the resulting bits while maintaining the proper S/N ratio, the convergent block floating point (CBFP) algorithm is used for the effective internal bit rounding and their method contributed to a single chip design of digital audio broadcasting system.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.1
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• pp.33-40
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• 1990

The purpose of this study is to suggest objective basic data for the apartment interior landscape project through the quantitative analysis of the apartment residents' satisfaction on the apartment interior landscape. 1. The major variables related to the interior landscape expert's satisfaction were the interest of the broadcasting of the interior landscape, garden belong to oneself, the intention of the modification of the apartment framework for the interior plantscape, the illumination for the indoor Plants, the season feeling through the int erior plantscape, the psychological effect of the indoor plants, income, the apartment framework and interior plants, the experience and knowledge about the indoor plants, floor space, utilizing veranda as a garden. 2. The major variables related to the general residents' satisfaction included the experience and knowledge on the indoor plants, veranda space, the season feeling through the interior plantscape, the illumination for the interior plants, the interest of the broadcasting of the interior landscape, the intention of the modification of the apartment framework for the interior plantscape. 3. According to the multiple regression analysis, the 'R2'of the major variables related to the experts' satisfaction has been obtained as 75.55%, and that of the varibles related to the general residents' satisfaction, 23.49 %. 4. Such variables as the season feeling through the interior plantscape, the Interest of the broadcasting of the interior landscape, and the intention of the modification of the apartment framework for the interior plantscape for the exports and the general residents are supposed that we develope new interior plants as well as the interior plantscape for the growth of the plants regarding the apartment framework. 5. The interior landscape experts were more positive than the general residents in using the interior landscape materials including indoor plants. 6. The feelings about building layout and the satisfaction in exterior spaces expended the interior landscape, visually, were reasons for the satisfaction of the apartment interior landscape.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1330-1336
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• 2021

Media sharing platform such as YouTube have grown significantly in the mobile environment. This is a platform that allows users to select and view broadcast programs that are only available on TV through network-connected PCs and mobiles, and share their media content to communicate. Currently, in the era where mobile and TV broadcasts can be viewed equally, there is a time difference between the video and real-time screen transmitted to TV and mobile, different from the actual situation.We want this time difference to be realized in the same way as the real time, and there is a need for a system that can broadcast in a free environment at any time. Therefore, in this paper, a broadcasting system was designed and implemented in a mobile environment. The result of reducing the delay time difference due to the improvement of the processing method was obtained.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.8-14
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• 2020

Recently, there was an increasing demand for an integrated access control system which is capable of user recognition, door control, and facility operations control for smart buildings automation. The market available door lock access control solutions need to be improved from the current level security of door locks operations where security is compromised when a password or digital keys are exposed to the strangers. At present, the access control system solution providers focusing on developing an automatic access control system using (RF) based technologies like bluetooth, WiFi, etc. All the existing automatic door access control technologies required an additional hardware interface and always vulnerable security threads. This paper proposes the user identification and authentication solution for automatic door lock control operations using camera based visible light communication (VLC) technology. This proposed approach use the cameras installed in building facility, user smart devices and IoT open source controller based LED light sensors installed in buildings infrastructure. The building facility installed IoT LED light sensors transmit the authorized user and facility information color grid code and the smart device camera decode the user informations and verify with stored user information then indicate the authentication status to the user and send authentication acknowledgement to facility door lock integrated camera to control the door lock operations. The camera based VLC receiver uses the artificial intelligence (AI) methods to decode VLC data to improve the VLC performance. This paper implements the testbed model using IoT open-source based LED light sensor with CCTV camera and user smartphone devices. The experiment results are verified with custom made convolutional neural network (CNN) based AI techniques for VLC deciding method on smart devices and PC based CCTV monitoring solutions. The archived experiment results confirm that proposed door access control solution is effective and robust for automatic door access control.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.90-104
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• 2020

It is difficult for non-experts to build machine learning (ML) models at the level that satisfies their needs. Deep learning models are even more challenging because it is unclear how to improve the model, and a trial-and-error approach is not feasible since training these models are time-consuming. To assist these novice users, we examined how interactive and explainable feedback while training a deep learning network can contribute to model performance and users' satisfaction, focusing on the data preparation process. We conducted a user study with 31 participants without expertise, where they were asked to improve the accuracy of a deep learning model, varying feedback conditions. While no significant performance gain was observed, we identified potential barriers during the process and found that interactive and explainable feedback provide complementary benefits for improving users' understanding of ML. We conclude with implications for designing an interface for building ML models for novice users.

• Korean Business Review
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• v.18 no.2
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• pp.133-149
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• 2005

DAB is meeting with mixed success. Denmark is performing similarly to the UK thanks to the innovation of the public broadcaster but where DAB is not so strong, the problem can usually be pointed at the lack of enabling regulation. The UK's example, whilst not appropriate everywhere, has valuable lessons including licensing incentives for existing analogue commercial broadcasters and a market-building obligation on the national multiplex licensee. Despite the obvious success of DAB, it would be an omission to leave some of the continued criticisms unanswered, whether of its slow start or the underlying technology. True, there was much over-optimism in the mid-1990s, coupled with unrealistic promises and expectations of receiver pricing and consumer take-up. Governments across Europe have legislated for DAB digital radio in a variety of ways but few as successfully as the UK. It is essential that both public and private broadcasters are encouraged equally to participate in digital radio. The UK is fortunate because, for the last 10 years, there has been a progressive government policy towards digital broadcasting. The 1996 Broadcasting Act set out a full licensing regime for both digital television and digital radio. The 1996 UK legislation contained a number of key elements which have been cornerstones of its success. DAB digital radio began test broadcasting around ten years ago but it has not been a universal consumer success across Europe. In the UK, however, digital radio receivers are one of the fastest-selling consumer electronics products and sales have overtaken those of analogue radios. Why has the UK succeeded with DAB digital radio when other European countries have yet to see their markets take off? This article explains what steps the UK took to make DAB digital radio a success.

• 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.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.31-34
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• 2015

Recently, the various types of data are began to increase. In order to manage the data efficiently, a variety of cloud services are being made. However, while providing a cloud service, the problem is the cost and waste a lot of human power to manage the data that is generated and managed by the server. To solve this problem, it is build the cloud environment using a single board computer with Raspberry pi. In this paper, we used Raspberry pi as a cloud server to provide services for the users. And we construct a Total Server to manage the generated data. It can separate the processing of data and the provision of services. We ensure the efficient operation by building a cloud environment with Raspberry pi and by managing the data which generated in cloud environment with the total server.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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• pp.377-390
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• 2011

A common problem encountered in product or process design is the selection of optimal parameter levels which involves simultaneous consideration of multiple response variables. This is called a multiresponse problem. A multiresponse problem is solved through three major stages: data collection, model building, and optimization. Up to date, various methods have been proposed for the optimization, including the desirability function approach and loss function approach. In this paper, the existing studies in multiresponse optimization are reviewed and a future research direction is then proposed.