• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.5A
• /
• pp.417-425
• /
• 2007

While the cyclic prefix lengths of downlink OFDMA(Orthogonal Frequency Division Multiple Access) systems are determined based on the maximum delay spreads encountered in cellular environments, the guard interval of uplink OFDMA systems should consider the timing offsets of uplink signals as well as the delay spread lengths. Especially in the cases of initial accesses, handovers, and considerable time elapsed without data transmissions between base and mobile stations in a large cell, uplink timing offsets can be large and a very long guard interval length may be required. In order to keep the small size of the cyclic prefix in uplink OFDMA systems, the systems require a method of extending the guard intervals for users with large timing offsets without affecting the cyclic prefix length of the system. This paper proposes a method extending the guard intervals of individual users in uplink OFDMA systems.

• Korean Security Journal
• /
• no.5
• /
• pp.157-178
• /
• 2002

The objectives of this study is to analyze the curriculum based on the hypothesis of bodyguarding related department and to research the differences of the amongthree groups of public bodyguarding, private bodyguarding and bodyguarding professors with its significance in order to establish the development of direction in education curriculum for bodyguarding related departments at university level,For this purpose, this study categorized the sample group into three kind and surveyed them, Those are public bodyguarding members, private bodyguarding member, and the professors and 121 samples were selected in those three with the help of self-admistrated method, which is one of the sampling methods, First, among the current bodyguarding related theoretical disciplines significant differences among groups was presented by the evaluations on bodyguarding science, traffic safety management, fire extinguishing, secretary science, administration, psychology, sports education, sport physiology, jurisprudence and philosophy, which showed differences among groups through the multiple comparison, But there was no significant difference among the means of the groups concerned with the other curriculum, We could know that more curriculum is needed to facilitate the private bodyguarding in disciplines and system of the current theory in this study. For it is predicted the demand for the private bodyguarding will increase continuously in the future. for which we should prepare. Thus it is required to increase the theoretical curriculum of the private bodyguarding. That is. the models of curriculum like introduction to machinary guarding. introduction to communication. computer theory and so on are required to be established. In addition to that. it must be noticed that the current private bodyguarding is not guaranteed by the legitimate institution. But the private bodyguarding is related to the police service. thus the curriculum of jurisprudence and police science should be studied together.

• The Journal of Society for e-Business Studies
• /
• v.9 no.3
• /
• pp.227-241
• /
• 2004

With the expansion of internet usage and the advanced technology for information and communication, the international e-Trade environment gradually migrates from the VAN/EDI to the global Internet-based e-Traed on an ebXML framework. In an effort to provide a Internet-based e-Trade environment with a security and trust, this paper analyzes security components and proposed the SSL and ebXML security technologies in order to assure of the trust and security over Internet-based e-Trade. In addition, this paper presents 3-phase methodology to realize the secure and trustworthy Internet-based e-Trade. In summary, as the first phase, the e-Trade business processes are re-engineered and the digital signature council for mutual recognition is orgainzed. And as the second phase, the Internet-based e-Trade system and the concerned digital signature technology are implemented. Finally as third phase, the PKI mutual recognition agreement is signed by parties concerned and then the Internet-based e-trade business is started. Furthermore, this paper presents the promising Internet-based e-Trade models where the digital signature can be applied.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.7
• /
• pp.47-57
• /
• 2014

In order to publicly notify the information security (Internet or Cyber) threat level, the security companies have developed the Threat Meters. As the physical security devices are getting more intelligent and can be monitored and managed through networks, we propose a physical security threat meter (PSTM) to determine the current threat level of physical security; that is a very similar compared with the one of information security. For this purpose, we investigate and prioritize the physical security events, and consider the impact of temporal correlation among multiple security events. We also present how to determine the threshold values of threat levels, and then propose a practical PSTM using the threshold based decision. In particular, we show that the proposed scheme is fully implementable through showing the block diagram in detail and the whole implementation processes with the access controller and CCTV+video analyzer system. Finally the simulation results show that the proposed PSTM works perfectly under some test scenarios.

• Journal of Digital Convergence
• /
• v.16 no.3
• /
• pp.385-394
• /
• 2018

The purpose of this study was to examine the effects of hospital organizational culture, organizational silence and job complexity on turnover intention in nurses working in general hospitals. The subjects were 152 nurses working at general hospitals. Data were collected from April 19, 2017 to April 30, 2017, and statistical analysis was analyzed by hierarchical multiple regression analysis using the SPSS/WIN 22.0 program. As a result of the research, turnover intention showed a positive correlation with resignation and defensive silence, whereas there was negative correlation between consensual organizational culture, sacrifice, suitability and connection of job inclination. The factors affecting the turnover intention were the present work experience, defensive silence, sacrifice, and the explanatory power of turnover intention was 47%. Therefore, in order to lower the turnover intention, it will be necessary to provide various programs to change the communication pattern in the nursing organization, and to provide differentiated welfare system.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.8
• /
• pp.9-16
• /
• 2007

Currently, the measurement of RF parameters for a base station in operation is typically limited to easily measured forward path items. In this paper, the forward monitoring ports of base stations are used to measure the reverse RF performance. The system has been implemented and effectiveness has been proven on an operating base station. The receiver sensitivity is measured using an internal CDMA modem which is used to monitor the output power based on closed loop power control when the modem is connected to the base station via a voice call. In order to improve accuracy, in addition to the modem Tx adjust(TxAdj) parameter, the detector's actual measurement is used. For accurate receiver sensitivity, the measurement should be made when there is no traffic which is not possible on an operating base station. Therefore, pilot channel chip energy to received signal power spectral density ratio$(E_c/I_o)$ compensation method is used to offset the receiver sensitivity degradation with voice traffic increase.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.25 no.3
• /
• pp.9-28
• /
• 2014

As a new library system, the 'human library', in which a man becomes an information resource, provides a library service through face-to-face communication in delivering knowledge and information to users. Since the human library exchanges information with 'human books', it shows some characteristics that are different from traditional library services and connotes some meanings as a new library service. In that, this study focuses on the human library of Seongbuk-Gu, Seoul. Specifically, in order to enhance our understanding of the human library, this study looks into the theoretical underpinnings and the background of human library in Seongbuk-Gu, examines the case of the human library in Seongbuk-Gu, analyzes the factors that influence the human library, and makes some suggestions for improvement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.3
• /
• pp.311-318
• /
• 2014

Electromagnetic compatibility(EMC) performance of the first Korea space launch vehicle(KSLV-I) should be ensured and verified in order to guarantee the normal operation among the spacecraft, ground facilities which are installed in the space center, and other wireless communication networks. For the purpose of the EMC performance verification, pertinent EMC test specifications, methods, and procedures for both the subsystems and the system should be established in consideration of operational properties and electromagnetic environmental effects. And it is required to maintain and control the EMC properties consistently in accordance with the determined specifications up to the program closing phase. In this paper, sequential management work conducted during the overall development process of the KSLV-I is explained, and not only the phased EMC test plan for each model of the KSLV-I and its subsystem but also test method, specification, and results of the verification tests are presented. And also, multipaction analysis results are presented.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.10
• /
• pp.2121-2128
• /
• 2012

This paper proposed the real time face area detection using Wavelet transform and the strong detection algorithm that satisfies the efficiency of computation and detection performance at the same time was proposed. The detected face image recognizes the face by configuring the low-dimensional face symbol through the principal component analysis. The proposed method is well suited for real-time system construction because it doesn't require a lot of computation compared to the existing geometric feature-based method or appearance-based method and it can maintain high recognition rate using the minimum amount of information. In addition, in order to reduce the wrong recognition or recognition error occurred during face recognition, the input symbol of Hidden Markov Model is used by configuring the feature values projected to the unique space as a certain symbol through clustering algorithm. By doing so, any input face will be recognized as a face model that has the highest probability. As a result of experiment, when comparing the existing method Euclidean and Mahananobis, the proposed method showed superior recognition performance in incorrect matching or matching error.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.252-255
• /
• 2011

Growing demand for smart phones and data communication diminishes the constraints of Twitter and Facebook than a smartphone has become a subject of interest. On the other hand facebook users in their relationships to obtain the consent of the other, twitter is a relatively simple procedure for the information ripple effect is excellent. Twitter is beyond a simple social networking services(SNS) located in one of the popular media and powerful have the upper retweet. Retweet to the top of his sympathy with the ability th send tweets to their subscriber information can spread quickly. In this paper, we propose the smart retweet that system actively extend the existing retweet. In order to realize the smart retweet and additional criteria for determining the destination of the information is required. Based on tweet generated regional or an local information mentioned to tweet, to determine the destination. Smart retweet of the speed and scope of information transmission through the scale is expected.