• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.191-200
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• 2010

The "intelligent internet power outlets" realized in this study use Internet environment to connect electrical and electronic products to the Net as well as to enable remote monitoring and control. They also have temperature and light sensors, and even offer scheduling options by means of a universal calendar run by an inner real-time timer. Furthermore, they control 4 outlets handling 4 external input conditions and infrared remote control with easy-to-use functions for home automation control. The user interface is equipped with an embedded Web server and UDP protocol handler, and which also allows special control programs be used with the Web browser. Thus, installing this real-time power control function with optimal scheduling and various communication functions will provide you with energy-efficient power outlets outfitted with the increasingly popular "standby power" electric power efficiency.

• Journal of the Korean Magnetics Society
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• v.26 no.4
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• pp.137-141
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• 2016

There is a growing demand for non-contact current measurements for efficient use of electrical power and energy saving. In this study, I propose a non-contact current sensor using LC resonance by a resonance circuit composed of a sensor coil and 2 coupling coils for enabling a wireless measurement. The inductance of the sensor coil, which could be changed by applied current, causes the change of resonance frequency of the resonance circuit. A pair of magnet was attached to the ferrite core to apply a bias magnetic field that enabled the determination of the current direction. We obtained an output voltage change of 18 V with the current of -3~3 A. But, the output was nonlinear. In order to realize the non-contact current measuring method proposed in the present study, there is a need for a strict investigation of linearity and resolution for the future study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.855-860
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• 2017

One of the most important issues in Wireless Sensor Networks is to save energy of the sensor node. But transmission latency is also the problem to solve for some applications such as military surveillance, object tracking. In these applications sensor node needs to send lots of data in limited time when an even such as object appearance occurs. So a delay efficient data transmission method is required. In this paper we propose a MAC protocol adequate for those applications. This paper proposed a low delay data transmission mechanism for military surveillance in wireless sensor networks. In the MAC protocol, a receiver node sends another beacon frame to sender node after receiving data packet. Using this second beacon frame, fast hop-to-hop transmission can be performed. Results have shown that the proposed MAC control mechanism outperformed RI-MAC protocol in the terms of latency.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.49-56
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• 2007

The IEEE 802.15.4 low rate wireless personal area network is a protocol suitable for wireless sensor networks. Thus there has been growing interest in the IEEE 802.15.4 protocol in the home automation networks. This paper proposes a scheduling scheme obtaining optimal parameters regarding the IEEE 802.15.4 frame and subframes in the home automation networks. Guaranteed time slots (GTS) are exploited for the delivery of real-time traffic. Given a set of the requirements for bandwidths and periods assigned to nodes in the network, the beacon interval and the active/inactive subframe duration satisfying the requirements are selected considering the low duty cycle by the proposed scheme. Based on these parameters, analytic results provide the way to efficient use of network resources including energy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1057-1069
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• 2017

The applications of Wireless Sensor Networks (WSN) are progressively adopting for various smart home services such as home automation, controlling smart home household appliances, constrained application services in a smart home, etc. However, enabling a seamless and ubiquitous WSN communication between the smart home appliances is still a challenging job. Therefore, in this paper, we propose a smart home control system using an Actuator based ZigBee networking (AZNET). The working of the proposed system is further divided into three phases, 1) an interference avoidance system is adopted to mitigate the effect of interference caused due to the co-existence of IEEE 802.11x based wireless local area networks (WLAN) and WSN, 2) a sensor-based smart light control system is used to fulfill the light requirement in the smart home using the sunlight with light source, and 3) an autonomous home management system is used to regulate the usage time of the electronic appliances in the smart home. The smart is tested in real time environment to use the sunlight with light sources in a various time of the day. Similarly, the performance of the proposed smart home is verified through simulation using C# programming language. The results and analysis revealed that the proposed smart home is less affected by the interference and efficient in reducing the energy consumption of the appliances available in the smart home scenario.

• Journal of Information Processing Systems
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• v.16 no.5
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• pp.1196-1213
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• 2020

There is a growing interest in the development of smart environments through predicting the behaviors of inhabitants of smart spaces in the recent past. Various smart services are deployed in modern smart cities to facilitate residents and city administration. Prediction algorithms are broadly used in the smart fields in order to well equip the smart services for the future demands. Hence, an accurate prediction technology plays a vital role in the smart services. In this paper, we take out an extensive survey of smart spaces such as smart homes, smart farms and smart cars and smart applications such as smart health and smart energy. Our extensive survey is based on more than 400 articles and the final list of research studies included in this survey consist of 134 research papers selected using Google Scholar database for period of 2008 to 2018. In this survey, we highlight the role of prediction algorithms in each sub-domain of smart Internet of Things (IoT) environments. We also discuss the main algorithms which play pivotal role in a particular IoT subfield and effectiveness of these algorithms. The conducted survey provides an efficient way to analyze and have a quick understanding of state of the art work in the targeted domain. To the best of our knowledge, this is the very first survey paper on main categories of prediction algorithms covering statistical, heuristic and hybrid approaches for smart environments.

• Convergence Security Journal
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• v.7 no.2
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• pp.107-118
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• 2007

Distributed wireless sensor network in various environment have characteristic that is surveillance of environment-element and offering usefully military information but there is shortcoming that have some secure risks. Therefore secure service must be required for this sensor network safety. More safe and effective techniques of node administration are required for safe communication between each node. This paper proposes effective cluster-header and clustering techniques in suitable administration techniques of group-key on sensor network. In this paper, first each node transmit residual electric power and authentication message to BS (Base-Station). BS reflects "Validity Authentication Rate" and residual electric power. And it selects node that is more than these regularity values by cluster header. After BS broadcasts information about cluster header in safety and it transmits making a list of information about cluster member node to cluster header. Also, Every rounds it reflects and accumulates "Validity Authentication Rate" of former round. Finally, BS can select more secure cluster header.

• Journal of the Korean Dietetic Association
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• v.9 no.2
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• pp.159-171
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• 2003

The food composition tables are frequently used to health and nutrition practices. But it is difficult to find out food exchange lists with food exchange groups in the food composition table. Over 2500 items and many kinds of nutrients are in the food composition table. But now food exchange lists are used a few foods. The internet demands the users needs for obtaining more food exchange lists and nutrient information from food composition. This basic study is to solve the users need and the supply more efficient and effective manipulation system for e-food exchange database construction and search system:ENECC/e-food exchnage(E-Nutrition Education and Couseling Center/e-food exchange). This paper introduces the food exchange database construction and search system(ENECC/e-food exchange) using the formula which calculates the food exchange quantity of 6 food exchange groups and added one extra groups(alcohol) based on the internet. The ENECC/e-food exchange database is basically based on the 6th food composition table(2001) of the National Rural Living Science Institution in Rural Development Administration, Korea. The e-food exchange database are consisted of 2,261 foods in 6 basic food groups and one extra groups by using ENECC calculating formula. Also, the e-food exchange database has the proximate composition, mineral and vitamin content such as energy, moisture, protein, fat, carbohydrate, ash, calcium, phosphorus, iron, sodium, potassium, retinol equivalent, retinol, â-carotene, thiamin, riboflavin, niacin, ascorbic acid, refuse per 100g of each food.

• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.339-345
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• 2017

Carbonaceous adsorbent (CA-WTP) was prepared by heat treatment at $400^{\circ}C$ for 2 h in N2 atmosphere using waste tire powder (WTP). WTP and CA-WTP were first characterized by thermo-gravimetric analysis (TGA), energy dispersive X-ray spectrometer (EDS), scanning electron microscopy (SEM), specific surface area analysis (BET) and FT-IR spectroscopy. Then, they were tested as adsorbents for removal of Cd in water. CA-WTP exhibited much higher specific surface area and total pore volume than WTP itself and showed higher adsorption capacity for Cd. Equilibrium data of adsorption were analyzed using Freundlich and Langmuir isotherm models. It was seen that both Freundlich and Langmuir isotherms have correlation coefficient $R^2$ value larger than 0.95. The results of studies indicate that CA-WTP developed from WTP by heat treatment could be used as efficient adsorbent for the removal Cd from water.

• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.322-329
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• 2009

Many researches in wireless sensor networks have used a geographic routing to effectively disseminate data between sinks and sources. To know the location information, the geographic routing has proposed two manners. A sink-initiated and a source-initiated are flooding to disseminate its location information in WSN. However, these two manners have two problems. Firstly, whenever they move, they flood their location information. Secondly, their location information is disseminated unnecessary nodes besides nodes which send and receive data in actually. Therefore, this paper proposes a protocol that can solve the two problems and disseminate effectively data between few sinks and few sources. The proposed protocol exploits a location information manager that manages location information of the sinks and the sources. We also compare the performance of the proposed protocol with the existing protocols through a simulation.