• Journal of Korea Multimedia Society
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• v.20 no.2
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• pp.271-278
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• 2017

This paper introduces a user-friendly PLC (programmable logic controller) monitoring and control system of heavy machinery using Android based smartphone. The proposed system will control diesel generator and many such like machine without a dedicated PC with respect to similar system and offers a new communication protocol for handling it. The smartphone controls the generator via Wi-Fi, through which it connects to the Raspberry pi which will be installed in the PLC panel to setup the communication between them. Furthermore, Raspberry pi connects to two devices, one is PLC which gives the status and current information of the machine and to ON/OFF the machine. This proposed system used RS485 as a key mediator for data exchanging between Raspberry PI(master) and PLC(slave). RS485 allows multiple devices (up to 32) to communicate at half duplex on single pair of wires and provides a long connectivity area (up to 1200 meters) as compared to another device. This proposed system specially focused on accurate data flow between smartphone and PLC panel.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.2
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• pp.106-115
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• 2013

LED lighting control system using unidirectional DMX512 (digital multiplex with 512 pieces of information)) protocol has been the most popular. Nowadays, the user's consumption has been upgrading to the more intelligent system but the upgrading process does not affect the existing infrastructure. There were many researches use the additional communication for the feedback communication way such as WiFi, Controller Area Network (CAN), Power Line Communication (PLC), etc but all researches had inherent disadvantages that created the independent feedback with the existing DMX512 system. Our paper represents the novel method that uses the remote device management (RDM) protocol to associate the additional feedback with existent DMX512 infrastructure in the one system. The data in DMX512 frame sending to the DMX512 client is split and repacked to become the RDM packet. This RDM packet is transferred to the RDM monitor console and the response RDM packet is converted to the DMX512 frame for control DMX512 client devices. This is the closed loop control model which uses the bidirectional convertibility between RDM packet and DMX512 frame. The proposed method not only upgrades the feedback control function for the old DMX512 system without changing the existent infrastructure, but also solves compatible problems between new RDM devices and old DMX512 devices and gives the low cost solution for extending DMX512 universe.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.880-881
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• 2016

디지털액자가 고전적 액자의 향취를 주며 또한 사진을 바꿀 수 있는 기능도 제공하지만 아직 새 흐름이 되는 못했다. 그 이유는 비싼 가격과 사진을 전송하기가 불편하기 때문이다. 우리는 디지털 액자로 사진 전송을 쉽게 하고, 거기에 더하여 위젯과 보안 기능을 추가하는 연구를 하였다. 사진 전송을 위하여 AWS(Amazon Web Service) 서버를 사용하는데 AWS 서버는 언제 어디서나 원할 때면 사진을 WiFi로 전송할 수 있게 한다. 이는 현재 사용하는 USB나 SD 카드를 이용하여 디지털 사진을 전송하는 것보다 훨씬 편리하다. 우리의 디지털 액자를 사용하면 다른 사람과 사진 교환이 쉽고 따라서 가족, 친구, 동료 사이의 친밀감도 쉽게 높일 수 있다.

• Journal of Information Technology Services
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• v.15 no.1
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• pp.289-298
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• 2016

There are continuos tendencies toward that foreign tourists increase. Since 55% of them visit Korea without data communication for saving the communication costs, they can not utilize a variety of O2O services through QR/NFC/Beacon. There have been some researches to provide a smart map service based on the micro webpage technology even without data communication. But, they do not suggest how the templates are retrieved into their smart-phones. In this paper, we describe a mobile tourist information system for those who have no data communication. We utilize the micro webpage technology to develop a system for market promotion, shopping goods, and tourist maps. What matters in the micro webpage techniques is that the templates should be already downloaded to the users' smart phones before using it. The preceeded research did not mention the problem. We suggest a scheme that tourists obtain the tremplates in the information offices on the spot through Wi-Fi. We describe the details of the system, and evaluate the data overhead of templates and the time to be downloaded. We show that the overheads are endurable, which means that the system would be working well.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.1227-1230
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• 2005

최근 다양한 네트워크의 융합(Convergence) 추세에 따라 기존 PSTN 서비스도 인터넷에서 VoIP 형태로 제공이 되고 있다. 하지만 VoIP 서비스는 인터넷망을 이용하므로 부여된 발신번호 정보를 송출하지 않아 발신자의 위치 및 해당지역의 공공구조기관(PSAP)의 식별이 불가능하여 긴급서비스 지원을 위한 위치정보 제공을 못하는 문제점이 제기되었다. 최근 측위기술의 활용이 다양해지고 요구수준이 높아짐에 따라 실내에서의 신호 차폐 문제점을 극복할 수 있고, 높은 위치정확도 등을 제공하는 WLAN와 RFID 기술을 이용한 측위기술 연구가 활발하다. 따라서 본 논문에서는 Wi-Fi, RFID, GPS를 이용한 측위기술을 사용하여 무선이동통신 환경에서 VoIP 긴급서비스를 지원하기 위한 모델 제안과 각 구성요소에 대한 기능, 세부적인 지원 절차를 설명하고, 위치정보의 획득 및 처리를 위한 운용 시나리오에 관한 구체적 방안과 제안모델을 적용하기 위한 고려사항에 대한 분석결과를 제시한다. 그 결과 제안된 모델은 무선이동통신의 긴급서비스 설계시 적용이 기대된다.

• Journal of Information Processing Systems
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• v.12 no.3
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• pp.436-454
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• 2016

This research presents the battery discharge rate models for the energy consumption of mobile phone batteries based on machine learning by taking into account three usage patterns of the phone: the standby state, video playing, and web browsing. We present the experimental design methodology for collecting data, preprocessing, model construction, and parameter selections. The data is collected based on the HTC One X hardware platform. We considered various setting factors, such as Bluetooth, brightness, 3G, GPS, Wi-Fi, and Sync. The battery levels for each possible state vector were measured, and then we constructed the battery prediction model using different regression functions based on the collected data. The accuracy of the constructed models using the multi-layer perceptron (MLP) and the support vector machine (SVM) were compared using varying kernel functions. Various parameters for MLP and SVM were considered. The measurement of prediction efficiency was done by the mean absolute error (MAE) and the root mean squared error (RMSE). The experiments showed that the MLP with linear regression performs well overall, while the SVM with the polynomial kernel function based on the linear regression gives a low MAE and RMSE. As a result, we were able to demonstrate how to apply the derived model to predict the remaining battery charge.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4A
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• pp.309-315
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• 2009

Wireless Ad-hoc networks are dynamic networks that consist of mobile nodes. Nodes in Ad-hoc networks are usually laptops, PDAs or mobile phones. These devices feature Bluetooth and/or IEEE 802.11 (WiFi) network interfaces and communicate in a decentralized manner. Due to characteristics of Ad-hoc networks, Mobility is a key feature of routing protocol design. In this paper, we present an enhanced routing maintenance scheme that cope with topology changes pre-actively. The key feature of the proposed scheme is to switch next-hop node to alternative neighbor node before link breakage for preventing route failure. From extensive experiments by using NS2, the performance of the proposed scheme has been improved by comparison to AODV protocol.

• The Journal of Asian Finance, Economics and Business
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• v.1 no.3
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• pp.37-42
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• 2014

The objective of the study is to find out the faculty members' perspective of most and least preferred parameters affecting the quality of education in an affiliated undergraduate engineering institution in Haryana, India. It is a descriptive research. The data has been collected with the help of Questionnaire Based Survey. The sample size for the study is 110. The respondents are the faculty members teaching B. Tech who were selected randomly from the above said geographical area. For data analysis and conclusion of the results of the survey, statistical tool like factor analysis was performed in SPSS. The most preferred aspects of the institution by the faculty members are: a secured Wi-Fi facility is well channelized to provide easy access, library is well equipped, faculty can visit the library with ease whenever they find time, toilets for the faculty are hygienic and in adequate number, parking facility for the faculty vehicle is spacious, adequate Industry Institute Interaction for the faculty development etc. The least preferred aspects of the institution by the faculty members are: faculty / staff rooms are spacious, well furnished and adequate in number, and working relationships between the Head of Departments and their faculty members are synchronized.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.284-288
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• 2015

Training power tiller operators in safe farming is necessary to avoid farming accidents. With the continuing progress in computational technology, driving simulators have become increasingly popular for conducting such training. Purpose: The objective of this study is to develop mock control devices and data acquisition apparatus for a tiller simulator. Methods: Except for the stand and tail wheel adjusting levers, the mock control devices were developed using a tiller handle assay. The data acquisition apparatus was realized using an embedded data-logging device and LabVIEW, the system design software. Results: The control devices of a real handle assay were successfully mimicked by the mock operator control devices, which used sensors for the relevant measurements. The data from the mock devices were acquired and transmitted to the main computer at intervals of 10 ms via Wi-Fi. Conclusions: The developed mock control devices operate similar to real power tillers and can be utilized in power tiller training simulators.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.3
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• pp.11-20
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• 2018

Smart devices refer to various devices and control equipment such as health care devices, imaging devices, motor devices and wearable devices that use wireless network communication (e.g., Wi-fi, Bluetooth, LTE). Commercial services using such devices are found in a wide range of fields, including home networks, health care and medical services, entertainment and toys. Studies on smart devices have also been actively undertaken by academia and industry alike, as the penetration rate of smartphones grew and the technological progress made with the fourth industrial revolution bring about great convenience for users. While services offered through smart devices come with convenience, there is also various security threats that can lead to financial loss or even a loss of life in the case of terrorist attacks. As attacks that are committed through smart devices tend to pick up where attacks based on wireless internet left off, more research is needed on related security topics. As such, this paper seeks to design an access control method for reinforced security for smart devices. After registering and authenticating the smart device from the user's smart phone and service provider, a safe communication protocol is designed. Then to secure the integrity and confidentiality of the communication data, a management process such as for device renewal or cancellation is designed. Safety and security of the existing systems against attacks are also evaluated. In doing so, an improved efficiency by approximately 44% compared to the encryption processing speed of the existing system was verified.