• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.2 no.1
• /
• pp.79-85
• /
• 1998

The 9-digit MMSI(Maritime Mobile Service Identity) in the NBDP is converted to the 7-digit identity signal, used to identify to the phase of and to synchronize to the clock of the ISS(Information Sending Station) automatically for phasing procedure between radio stations. In this paper, algorithms for the automatic identification phasing procedures and for conversions, calculations between 7-signals and 9-identity, those check-numbers in the phasing procedures for calling of the NBDP are discussed and designed. And a method of the faster locking and phasing for calling than that of recommended by ITU-R is suggested and implemented.

• The KIPS Transactions:PartD
• /
• v.13D no.3 s.106
• /
• pp.391-398
• /
• 2006

This paper verifies deployment algorithms in wireless sensor networks using SPIN, a widely used model checking tool. In this paper, two deployment algorithms, DSSA(Distributed Self Spreading Algorithm) and TBDA(Tree Based Deployment Algorithm), are verified to check their stability against oscillation as well as energy consumption that is an important factor in wireless sensor networks.

• The Journal of the Korea Contents Association
• /
• v.16 no.2
• /
• pp.68-81
• /
• 2016

This study suggests, based on analysis of current status, improvement plans for the local government's public mobile applications. Fist of all, this study selected analysis elements and established an analysis framework for public mobile applications. Then the study analyzed the applications developed by all local government and application management practices in Seoul-City. The status of public applications shows that there are no institutional guidelines and the practical use of the public application is low in relation to the invested costs. Additional problems are the imprudent development, non-reflection of demand, absence of systemic management. For the improvement plans, the study suggests understanding of exact demand, detailed examination of validity, offering of effective information and the utilization of double-way interaction application. The management side of the improvement plans addresses the preparing for public application ordinance, building proper management system, regular check, education and active promotion.

• Journal of Internet Computing and Services
• /
• v.20 no.5
• /
• pp.9-18
• /
• 2019

Android Application Package (APK) is vulnerable to repackaging attacks. Therefore, obfuscation technology was applied inside the Android APK file to cope with repackaging attack. However, as more advanced reverse engineering techniques continue to be developed, fake Android APK files to be released. A new approach is needed to solve this problem. A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a cryptographic hash of theprevious block, a timestamp and transaction data. Once recorded, the data inany given block cannot be altered retroactively without the alteration of all subsequent blocks. Therefore, it is possible to check whether or not theAndroid Mobile APK is forged by applying the blockchain technology. In this paper, we construct a discrimination DApp (Decentralized Application) against forgery Android Mobile APK by recording and maintaining the legitimate APK in the consortium blockchain framework like Hyperledger Fabric by Composer. With proposed DApp, we can prevent the forgery and modification of the appfrom being installed on the user's Smartphone, and normal and legitimate apps will be widely used.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.3
• /
• pp.217-225
• /
• 2016

In this paper, we propose an improved path planning method and obstacle avoidance algorithm for two-wheel mobile robots, which can be effectively applied in an environment where obstacles can be represented by circles. Firstly, we briefly introduce the rapidly exploring random tree (RRT) and single polar polynomial (SPP) algorithm. Secondly, we present additional two methods for applying our proposed method. Thirdly, we propose a global path planning, smoothing and obstacle avoidance method that combines the RRT and SPP algorithms. Finally, we present a simulation using our proposed method and check the feasibility. This shows that proposed method is better than existing methods in terms of the optimality of the trajectory and the satisfaction of the kinematic constraints.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.10A
• /
• pp.1480-1485
• /
• 2000

This paper presents an efficient synchronization sequency design for the digital cellular telephone. The class of synchronization sequences studied in this paper are sequences for synchronization that have the lowest out-of-phase values of the autocorrelation function with the two peak values equal in magnitude and opposite in polarity at zero and middle shifts. These synchronization sequences can be used to double-check synchronization timing and reduce the synchromication search time.

• Journal of Drive and Control
• /
• v.17 no.4
• /
• pp.15-22
• /
• 2020

With the need for efficient maintenance technology to reduce maintenance costs for steel bridges, repainting robots are being developed to automate the work in narrow and poor bridge spaces. The repainting robot is equipped with a blasting module to remove paint layers and contaminants. This study developed a prototype monitoring module to be mounted on the repainting robot. The monitoring module analyzes the condition of the painting surface through a camera installed in the front, guides the direction of movement of the robot, and provides the operator with a video to check the working status after blasting through a camera installed in the back. Various image visibility enhancement technologies were applied to the monitoring module to overcome worksite challenges where incomplete lighting and dust occurs.

• The Journal of the Korea Contents Association
• /
• v.16 no.4
• /
• pp.45-55
• /
• 2016

The purpose of this study was to identify the relation between mobile phone use and visual display terminal syndrome symptom experience in female students from middle school and high school. The convenience sample consisted of 349 female students in four schools. The data were collected from May to June in 2013 using VDTS Subjective Symptom Questionnaire. Descriptive statistics, Kruskal-Wallis test, and Mann-Whitney U test were used to analyze the data using SPSS 21.0. Almost all (96.3%) female students use mobile phone. Among them, 87.7% of the subjects experienced more than one VDTS symptom and the average score was $.39{\pm}.41$ in VDTS symptom experience. Eye related symptom was most experienced and musculoskeletal symptom was the highest in severity among five subdomain of VDTS symptoms. There were significant differences in VDTS symptom scores in accordance with posture, hours of use, and break type during mobile phone use. These findings suggest that the education program for adolescents would be necessary, and the development of checklist would be useful for adolescents to check themselves.

• ETRI Journal
• /
• v.21 no.2
• /
• pp.9-21
• /
• 1999

In this paper, to enhance the performance of ${\pi}$/4-DQPSK (${\pi}$/4-differential quadrature phase shift keying), the scheme using nonredundant multiple error correction is proposed and investigated. This scheme for the differential detection of ${\pi}$/4-DQPSK uses the signal output which is delayed for more than two time slots as the parity check bit and applies it to nonredundant multiple error correction. The proposed system was used for studying the performance of ${\pi}$/4-DQPSK with Nonredundant Error Correction (NEC) in additive white Gaussian noise (AWGN) and Nakagami fade modeled mobile communication channel, and it was observed that the performance increased as the error correction capability increased.

• Proceedings of the KSPS conference
• /
• 2002.11a
• /
• pp.119-122
• /
• 2002

This paper focuses on building up a database of commercial stocks using XML syntax and looks into a way of building up a system with the combination of XML and XSLT that provides connectivity to client-server databases through vocal means. The use of XSLT has several advantages. Most importantly, it can transform a type of data into different formats. A vocal interface minimizes some space and time limits imposed on users outside premises when they need an instant connection to their database. In this fashion, the users can check information on stock lists without being pressurized by certain limits. PC, PDAs and cellular phones are some examples of mobile connection. The use of VoiceXML creates vocal applications. In VoiceXML servies, users can gain immediate access to data upon the input of their voices and the DTMF signals of the telephone.