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In a wireless network consisting of Internet of Things (IoT) devices, they can harvest energy from radio frequency (RF) signals transmitted by Power Beacons (PBs) and consume energy by transmitting data to the Access Point (AP). As the number of devices increases in a network, an efficient Medium Access Control (MAC) protocol is required to enable devices to transmit data in an energy-efficient manner. In this paper, we propose an energy-efficient MAC protocol that operates with devices and backscatter tags that transmit data by reflecting the RF signal. In the proposed network, the AP manages the operation time of PBs after receiving data from devices according to the average amount of remaining energy. The proposed protocol can improve the network throughput and the energy efficiency of devices.

In cellular networks, User Equipments (UEs) must perform a Random Access (RA) process in which UEs are allocated resources for data transmission from the Base Station (BS). The 5G network using the high-frequency band adopts the beamforming technology in order to overcome the high path-loss. As the narrow coverage characteristic of the beam, the BS and UEs use the beam-sweeping and beam-switching methods at the RA process. In this paper, we propose an Enhanced Random Access (E-RA) process, in which the UE selects multiple preambles and transmits them through the beam-sweeping method, and transmits the Connection Request Message (Msg3) through the random beam-switching method. Furthermore, we also propose an improved re-access process that begins with Msg3 retransmission. Through the E-RA process, we can reduce the access delay of the network and the number of transmitted messages causing the energy consumption of the UE and increase the success probability of the RA process.

VHF Data Exchange System (VDES) is a wireless communication system between ships and shore stations in a marine environment. Recently, a standardization of VHF Data Exchange (VDE) to provide information and multimedia data exchange between ships and shore stations is underway. Unlike the conventional communication networks, the communication quality of marine networks is influenced by the height of the sea wave, the height of the shore stations, and the density and location of ships. In this paper, we propose how to utilize the VDE channels and a communication protocol such as Multiple Incremental Time Division Multiple Access (MITDMA) and Fixed Access Time Division Multiple Access (FATDMA) in order to implement the operation of ships and shore stations defined in the standard. Then we develop an OPNET simulator with the model of ships and shore stations and channel models. We evaluate the uplink data throughput considering the coastal environment in Korea and the network parameters of the VDE channels.

With the recent increase in IoT devices, network connectivity devices such as routers or switches are increasing. This increase in equipment could increase the degree of a particular node (hub node or hub router) in terms of network characteristics. In other words, the structure of the network can be changed into a more complicated network form. The convergence of links to these specific nodes provides an opportunity for attackers to enjoy maximum benefit at minimal cost. An attacker can attack only a few hub routers with a high degree of network structure, which can paralyze networks in some areas. This possibility is because the actual network follows the power degree distribution. These research measures threats based on network characteristics and data on exploits of network equipment. The threat measurement is applied to the FAIR(Factor Analysis of Information Risk) model, and the damage caused by the macro network structure is assessed.

The EU's GDPR is expected to come into force on May 25, 2018. By this regulation, it will be possible to enforce even stronger legislation than the existing Directive. In particular, GDPR is expected to have a major impact on IoT industry, which uses diverse and vast amounts of personal information. This paper first examines why the IoT industry is affected by GDPR. Then, the paper describes how the GDPR will affect the IoT firm's cost qualitatively by using the cost definition of the Gordon and Loeb model and quantitatively by estimating cost using statistics and legal bases. As a qualitative view, the GDPR affected the preventative cost and legal cost of the Gordon and Loeb model, and the quantitative view showed that after the GDPR, the firm's cost could increase by 3 to 4 times on average, and by 18 times if it was more.

DFNA5's mutations are known as the reason of autosomal dominant non-syndromic hearing loss (ADNSHL). To date, DFNA5 has been mostly experimented by particular families' DNA samples. By using three homo sapiens deafness sequences provided by ncbi, we investigated amino acid sequences in order to analyze relationships among mutants. We used apriori algorithm to find common amino acid which indicates a particular feature and decision tree C5.0 algorithm in order to discover the difference and what amino acid is likely to appear in each position. As a result, Leucine, Glycine, and Alanine were the most crucial amino acids to explain the relationship. This result made us to speculate that variant 2 and 3 are derived from variant 1. Hereby, our experiment suggests features of these mutants and arouses further research about how these amino acids affect the hearing-impaired.

In this paper, we propose a view composition method for co-training. In order to compose views properly, two assumptions should be satisfied. One is that two views are class-conditionally independent on each other; the other is that the classification information between labels and view is high. We apply Class-Conditional Independent Component Analysis (CC-ICA) to obtain new features which are mutually independent, and compose views hold a high classification information. We show that our method is promising and effective through the experiment.

This paper presents a Ideal Analytic Hierarchy Process which can provide an overall assessment of system performance. To obtain a unified index, this paper presents the scaled performance of each item, and propose the use of the AHP model with three states: [Ideal] - [Actual] - [Possible] states. By calculating eigenvalues of states, the unified index can be obtained. The proposed method is applied to assess power quality index which is especially useful for planning. The proposed method has been applied to a relatively large actual system, and the usefulness of this method has been verified.

This paper presents a unified approach for the computation of combined reliability and power quality (PQ) indices using a value-based methodology. An assessment methodology is presented to unify PQ considering load dynamics and cost-benefit relationships. The methodology is based on failure mode & effects analysis and an improved reliability and voltage sags assessment model in that includes load dynamics. PQ indices are first classified into mis-operations, aging, and losses, and then the indices from each class are converted into cost and summed. By converting diverse indices into cost, a unified index is obtained.

In this paper, we attached RFID tag on trees and compared the maximum distance that is read under rainy environment or for each recognition mode. Then, we analyzed the system’s maximum reading distance of 15 tags in total under various forestry environments such as clear day, rainy day, different reading method and different tag sizes. As an unprecedented research in the country to apply RFID to forestry, first it can provide basic information to be utilized to come up with specifications and elements for considerations to make customized tag appropriate under the forestry environment in the future. Second, this study can also be used as a foundation to make a manual for field operations which utilizes RFID under forestry environment.

This paper presents a unified power quality index based on the ideal analytic hierarchy process, which can provide an overall assessment of distribution system performance. To obtain the unified power quality index, this paper presents the scaled performance of each power quality item, and propose the use of the AHP model with three states: [ideal]-[actual]-[possible] states(Ideal AHP). By calculating eigenvalues of states, we obtain the unified power quality index. The proposed method is especially useful and effective for planning. The proposed method has been applied to a relatively large actual system, and the usefulness of this method has been verified.

The connected dominating set (CDS) has been extensively used for routing and broadcast in mobile ad hoc networks. While existing CDS protocols are successful in constructing CDS of competitive size with localized information, they either lack the mechanism to properly handle nodal mobility or require lengthy period of time to recover when CDS becomes corrupted. In this paper, a novel protocol, namely Multi-Initiator Connected Dominating Set protocol (MI-CDS), is proposed that constructs and maintains CDS of competitive size efficiently without introducing much communication overhead. The simulation results demonstrate that MI-CDS permits CDS to be available for the highest percentage of time in the mobile network scenario compared with the other CDS protocols.

This paper presents a planar ultra-wideband (UWB) antenna with band rejection characteristic for UWB communications. A planar rectangular patch is printed on a PCB with epsiv=4.4 (FR4) and the volume of this antenna is 30times30times1.6 mm3. To obtain the band rejection characteristic, we made the partial ground with width of 30 mm and length of 2 mm on the other plane of the patch. By adding a branched feed line, we obtained increased bandwidth. Also, the addition of bevels on both edges of a rectangular patch increased the bandwidth. For the optimized parameters, simulations are performed by using ANSOFT HFSS. The average measured return loss is -8.2 dB in 3.1 ~ 4.8 GHz low band and it shows not so good characteristic. But band rejection characteristic in 4.9 ~ 6.8 GHz band shows better performance than the simulation. This antenna provides nearly same H-plane patterns at 5 GHz between the simulation and the measurement but it shows a marked difference at 6 GHz. And the group delay is less than 1.2 ns with a little variation except the maximum 4.2 ns at 7.17 GHz. If the return loss in low band can be improved, this proposed antenna will satisfy the UWB specifications of the MIC (ministry of information and communication) of Korea.

In this paper, we made a high power amplifier module package using a selectively anodized aluminum substrate for the X-band radar T/R modules. The proposed solution of package is based on thick anodized aluminum oxide (Al2O3) layers and power chips mounted on aluminum for an effective heat sink. The fabricated high power amplifier module has a maximum output power of 39.49 dBm and maximum gain of 32 dB over 9 - 10 GHz frequency band. This package method can be further contributed to decreasing cost, reducing module size and managing thermal problem for the microwave high power T/R modules.

Thick RF transmission lines and spiral inductors were made using polymer-core conductor. The proposed fabrication process to make polymer-core conductor is very easy and cost effective compared with other RF MEMS processes. SU-8 photoresist was used as core. The fabricated transmission line and spiral inductors on a HRS (high resistivity silicon, 2500 Omegaldrcm) have S21 of 0.08 dB/mm at 18 GHz and high Q factor more than 40 at 2 GHz respectively.

As online information services have become widespread in the Web nowadays, conversational agents appear as an effective and familiar user interface. Since conversational agents analyze the user's query based on a static process, it cannot manage complex expressions. In this paper, we propose semantic Bayesian networks that infer the user's intention based on Bayesian networks and their semantic information representing the relationship among nodes. Since conversation often contains ambiguous expressions, managing the context or the uncertainty should be necessary to support flexible conversational agents. The proposed method drives the mixed initiative interaction (MII) that prompts for missing concepts and clarifies for spurious concepts to understand the user's intention correctly. Actually implementing a Web information guide with the proposed method, we have confirmed the usefulness of the proposed method.

This paper suggests a method to recognize the various defect patterns of a cold mill strip using a binary decision tree. In classifying complex patterns with high similarity like the defect patterns of a cold mill strip, the selection of an optimal feature set and an appropriate recognizer is important to achieve high recognition rate. In this paper the GA (genetic algorithm) and K-means algorithm were used to select a subset of the suitable features at each node in the binary decision tree. The feature subset with maximum fitness is chosen and the patterns are classified into two classes using a linear decision function. This process is repeated at each node until all the patterns are classified into individual classes. In this way, the classifier using the binary decision tree is constructed automatically. After constructing the binary decision tree, the final recognizer is accomplished by having a neural network learning sets of standard patterns at each node. In this paper, the classifier using the binary decision tree was applied to the recognition of defect patterns of a cold mill strip, and the experimental results are given to demonstrate the usefulness of the proposed scheme.