• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.2
• /
• pp.243-251
• /
• 2010

The military has been putting great efforts into applying data communication on existing voice communication systems being used in NCW(Network Centric Warfare). Data communication will be an effective choice in one of many effort to yield a minimum kill chain, comparing to legacy voice communications, when tactical units conduct their missions. However, the required budget will be enormous, in case of the replacement of a lot of legacy communication systems with new one. As a cost-effective alternative, the tactical data communication systems using the conventional radio systems instead of the development of new radio systems has been proposed. It is mandatory, though, to ensure QoS while maintaining data communication by making use of legacy radio systems already in use. This paper focuses on the performance issues experimented and analyzed for tactical data communication through the legacy radio systems as the first step towards guaranteed QoS. We have conducted various experiments such as the transmission error rate on certain tactical messages, performance evaluation of redundant transfers, the relationship between the transmission frame size and rate of error, the identification of error points in the transmission frame, and techniques to reduce the errors in both hopping and non-hopping modes. As a result of the performance experiments, The adaptive communication module which decides the redundant transmission or the Forward Error Correction(FEC) technique by analyzing channel status and current transmission status(hopping/non-hopping) of the legacy radio should be designed. the FEC technique in non-hopping, and the redundant transmission technique in hopping mode was recommended from the result of experiment with the frame size is 20bytes in non-hopping and 10Bytes frame size in hopping mode.

• Journal of Ubiquitous Convergence Technology
• /
• v.2 no.1
• /
• pp.18-26
• /
• 2008

The invariance relation existing in the non-negative matrix factorization (NMF) is used for constructing robust image hashes in this work. The image is first re-scaled to a fixed size. Low-pass filtering is performed on the luminance component of the re-sized image to produce a normalized matrix. Entries in the normalized matrix are pseudo-randomly re-arranged under the control of a secret key to generate a secondary image. Non-negative matrix factorization is then performed on the secondary image. As the relation between most pairs of adjacent entries in the NMF's coefficient matrix is basically invariant to ordinary image processing, a coarse quantization scheme is devised to compress the extracted features contained in the coefficient matrix. The obtained binary elements are used to form the image hash after being scrambled based on another key. Similarity between hashes is measured by the Hamming distance. Experimental results show that the proposed scheme is robust against perceptually acceptable modifications to the image such as Gaussian filtering, moderate noise contamination, JPEG compression, re-scaling, and watermark embedding. Hashes of different images have very low collision probability. Tampering to local image areas can be detected by comparing the Hamming distance with a predetermined threshold, indicating the usefulness of the technique in digital forensics.

• Journal of Convergence for Information Technology
• /
• v.10 no.2
• /
• pp.32-38
• /
• 2020

In this paper, we analyze the modulation scheme for high speed transmission in visible light communication system, and study non-orthogonal multiplexing, dimming level and transmission power ratio. Conventional visible light communication has a disadvantage in that it is difficult to multi-transmit to increase the transmission speed. Multi-transmission technique is necessary for high-speed transmission at the transmitter. Since general visible light communication has a limitation in multiple transmission, various researches for high-speed transmission have been conducted. In order to solve this problem, this paper proposes a multiple modulation scheme for high-speed visible light communication using non-orthogonal multiplex transmission scheme and a future research direction.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.12
• /
• pp.170-185
• /
• 2016

The purpose of this study was to investigate the relationship among instructor's non-verbal communication, emotional reaction, and self-efficacy. By using convenience sampling method of non-provability sampling, 258 student athletes from S and D cities were selected for a questionnaire survey. The 184 returned surveys were analyzed with structural equation modeling through SPSS 22.0 and AMOS 22.0 statics program. The study results are summarized as follows. First, instructor's non-verbal communication has a positive influence on emotional reaction of high school student athletes. Second, high school student athletes experiencing emotional reactions by instructor have a positive influence on self-efficacy. Third, instructor's non-verbal communication does not influence self-efficacy of high school student athletes directly. Fourth, emotional reactions of high school student athletes experienced by instructor's non-verbal communication have a mediating effect on self-efficacy. Fifth, neither gender nor exercise period has a moderating effect on the relationship between non-verbal communication, emotional reactions, and self-efficacy.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.6
• /
• pp.1901-1913
• /
• 2014

The IEEE 802.15.6 is a communication standard for Wireless Body Area Networks (WBANs). This standard includes a prioritized slotted Aloha as a choice for medium access control. This protocol is different from the traditional version as it has integral considerations for certain priorities of users. It attempts to resolve collision by halving the probability of retransmission, lower bounded by to a minimum, in the alternate slots to follow. In this paper, we present an analytical model to compute the non-saturated throughput of this protocol in the presence of finite number of nodes. The model is validated against simulation.

• English Language & Literature Teaching
• /
• v.7 no.2
• /
• pp.103-114
• /
• 2002

Language plays a central role in everyday communication activities. Therefore, an individual need to be able to use language to communicate with confidence and without fear. One of the major fears that people have is the fear of communication. This fear is most of the time due to a lack of confidence in communicating in a particular language or due to poor proficiency in the language. In some cases it can also be due to attitudinal problems. In the context of teaching and learning English as a second or foreign language, students can have a great fear of using English with confidence. This fear can be an acute one and thus students may avoid using English to communicate. However, non native speakers of English need to be highly competent in the use of the English language for a variety of communicative purposes particularly in meeting the challenges of globalisation and that of the digital age. This article presents some insights on language apprehension found among communication undergraduates who are non native speakers of English.

• International Journal of Contents
• /
• v.4 no.2
• /
• pp.24-28
• /
• 2008

In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.

• Korean Journal of Child Studies
• /
• v.30 no.5
• /
• pp.195-208
• /
• 2009

This research was a comparative study of children's mothers in counseling and mothers in non-counseling (comparison) groups to examine differences between groups in emotional expressiveness, ambivalence over emotional expressiveness, type of communication and parenting behavior, Subjects were 91 mothers having counseling and 133 mothers in the non-counseling group. Data were analyzed by independent samples t-test. Results showed that mothers in the non-counseling group reported more positive emotional expressiveness than the counseling group. Mothers in the counseling group reported more ambivalence over emotional expressiveness, more negative communications and more negative parenting behavior than the comparison group.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.540-543
• /
• 2003

This paper presents design and manufacture of RF type non-contact radiological dosage measuring device. It also concerns on the broad out-line and the ways of improvement about RF type non-contact radiation measuring device. Measuring radiological dosage with non-contact RF, the stability and efficiency of the measure have been improved by reforming constant current circuit. Furthermore, applying communication protocol in process makes it possible to achieve faster and more accurate communication than old circuit. On the base of those, RF type non-contact radiological dosage measuring device which consists of radiological dosage measuring module and Reader module has been designed and manufactured. While testing communication against embodied device, the possibility of the field application could be confirmed.

• Journal of Distribution Science
• /
• v.3 no.2
• /
• pp.121-142
• /
• 2005

We're living in a world of one global village. The globalization of business is acceleration as more companies cross national borders to find customers, materials and money. Many foreign companies and organizations are doing their business aggressively in Korea and many Korean companies and rushing into foreign market. When people communicate for business with someone from another culture, there could be difficult communication barriers to overcome resulting from differences in their values, beliefs, norms for behavior, expectations, attitudes and so on. To do successfully business, we need to understand culture background and communication style that is different from nation, race, language. Communication barriers stemming from cultural differences may vary. Largely, they can be divided into value system, non-verbal communication, and perception process. Value system can be divided into individualism versus group orientation, avoidance of uncertainty degree, power distance, and high- context culture versus low-context culture. Also non-verbal communication method and perception process may play decisive roles in communication effectiveness. Especially nonverbal communication barriers which sometimes play more important roles than the verbal parts are composed of eye contact, gesture, kinesics, proxemics, chronemics, paralanguage and language of color Cross-cultural communication affect business situation. I expect that if we understand cultural background, and then we overcome cross-cultural communication barriers. To overcome and to adapt inter-cultural business, we need to develope curriculum on the cross-cultural education which I will study in the next paper.