• Journal of Korea Multimedia Society
• /
• v.11 no.8
• /
• pp.1101-1110
• /
• 2008

Nespot provides a convenient wireless internet connection service. The existing IEEE 802.1X EAP-MD5 authentication mechanism can be achieved based on ID/password information for a wireless connection. The Nespot system offers an advanced accounting and authorization procedure for providing wireless user authentication mechanism. However, many problems were found on the existing Nespot EAP-MD5 mechanism such as a ill value exposure, a leakage of personal information on wireless authentication procedure and a weakness on Nespot mutual authentication mechanism. Therefore, we analyzed the limitation of the existing IEEE 802.1X EAP-MD5 certification system, and suggested a one-time session key based authentication mechanism. And then we offered a simplified encryption function on the Nespot certification process for providing secure mutual authentication process.

• International Commerce and Information Review
• /
• v.9 no.2
• /
• pp.19-40
• /
• 2007

In recent, T-commerce is widely dispersed as alternative type of commerce. It is forecasted that t-commerce system is used more than e-commerce system. Therefore more and more t-commerce-related industries are also recognizing that t-commerce is a critical business model. It is needed to understand the concept of t-commerce and develop the t-commerce marketing strategy. CEO analyses consumer's behaviors according to the data about buyers and applies the advantage of t-commerce to the communication with customers. This t-commerce system plays an important role in maximizing customer satisfaction and affecting their intention to reuse it. Therefore this paper attempts to identify T-commerce critical success factors and divide between use-intention group and unuse-intention group by taking out a discriminant function by the discriminant analysis. This lays a foundation in developing T-commerce strategy. According to the discriminant function extracted, convenience factor, amusement factor, system quality factor, product perception factor are significant in the sequence of influential degree. However, usefulness factor and speedy connection factor are not significant. In result, the target hitting rate is 77.9% in the first unuse-intention group and it is 95.2% in the second use-intention group. The total discriminant target hitting rate is computed to higher value, 86.55%. The statistic package, SPSS 12.0, is used to survey and analyse data and test the hypothesis. The validity and reliability of variables are verified by both reliability analysis and factor analysis. The discriminant analysis is used to tell the difference between use-intention group and unuse-intention group.

• Journal of Korean Library and Information Science Society
• /
• v.29
• /
• pp.65-103
• /
• 1998

This study aims to examine both the theoretical framework and practical method for the building a subject-oriented collection of information resources form Internet. Through the study, a few conclusions as well as a suggestion were derived. 1. Conclusions : (1) The continuous learning and studying by the librarians working in the information society is required in order that they could have a broader recognition of the existence of various resources from Internet by subject, and that they could be armed with a greater ability to evaluate for the information filtering. (2) The use of a subject directory to collect needed information resources form Internet revealed the necessity for going through many steps linked by hierarchical indexes till arriving at the desired information, and accordingly the great time was needed to conduct the work. (3) In case of using various search engines, since the output of the relevant information largely depends on the adequate defining of the topic, the right selection of search terms and the accurate methods of inputting the keywords, systematic organization of the resources is not simple and easy. The classifying work of collected resources for the topic into the broader categories differs from that of the resources form other topics, for example, psychology, because of the idiosyncrasy of the contents of the each topic. (4) As one method to provide more revolutionary value-added service using Internet, it is necessary for the librarians to learn the skills to build the Web resource pages of subject-oriented collection of information resources from Internet on the specific subject. 2. A suggestion : Since the study did not complete the collection and organization of the information resources from the Internet on this topic, the remaining research and task should be the thorough collection of resources and the building the Web resource pages consisting of interconnecting links of indexes by spending greater time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.453-456
• /
• 2007

In this paper, we describes a design of Wireless Mesh Network based middleware that applied into USN(Ubiquitous Sensor Networks). WMN based middleware is a technique which links data between widely distributed sensor devices and WMN for context-awareness. The use of WMN base middleware in this paper makes possible communication on insufficiently network constructed area by use of WMN. WMN based middleware also anaylze events comprehensively that originated from specific sensor device. Based on the result from analyzed data with predetermined value WMN based middleware will given an order to designated actuator devices. Middleware operate each function of sensor network management and application service separately.

• Progress in Medical Physics
• /
• v.30 no.2
• /
• pp.59-63
• /
• 2019

Purpose: To manage radiation measurement equipment, a web-based management program has been developed in this study. Materials and Methods: This program is based on a web service and Java Server Pages (JSP) and employs compatibility and accessibility. Results: The first step in the workflow has been designed to create accounts for each user or organization and to log in. The program consists of two parts: fields for listed instruments, and measurement information. The instruments for measuring radiation listed in this program are as follows: ionization chambers, survey meters, thermometers, barometers, electrometers, and phantoms. Instrument properties can be put in the recording fields and browsing for associated instruments can be performed. The main part of the program is the cross-calibration for each ion chamber. For instance, the ionization chamber to be used as a relative dosimeter can be registered by cross-calibration data with a reference chamber calibrated by an accredited laboratory. This program supports methods using the central axis transfer theory for cross-calibration for the ionization chambers. The reference and field ionization chambers were placed in a solid water phantom along the beam central axis at two different depths, and then the positions were switched. Each measured value was used for calculating the cross-calibration factor. Conclusions: Because many instruments are used and managed in radiation oncology departments, systematic, traceable recording is very important. The web-based program developed in this study is expected to be used effectively in the maintenance of radiation measurement instruments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.650-652
• /
• 2013

As VANET(Vehicular Ad-hoc NETwork) improves road safety, efficiency, and comfort, and provides a value-added service such as commerce information or internet access. it is the most important technology in ITS(Intelligent Transportation System). But, In VANETs, better communication efficiency can be achieved by sacrificing security and vice versa. VANETs cannot get started without either of them. Therefore, to solve these problems simultaneously, this paper proposes MAC(Message Authentication Code) based SDAP(Secure Data Aggregation Protocol) which removes redundant data or abnormal data between vehicles and verifies the integrity of message. The MAC based SDAP not only improves the efficiency of data delivery but also enhances the security by detecting malicious attacks such as propagation jamming attack, forgery attack, and disguised attack.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.12B
• /
• pp.1677-1685
• /
• 2001

In this paper, we propose a call admission control scheme that can be performed within guaranteeing of required QoS(Quality of Services) in DS-CDMA(Direct Sequence-Code Division Multiple Access) reverse link. It has been performed rely on a physical channel numberonly and based on quality of received signal from MODEM(modulator/demodulator) part in established study. In other methods, the standard for services would have been set from statistical analysis of users\` location and using received power level in BTS(Base Transceiver Station). These ways bring about not only system loads but time delay or great differences from real environment. To solve these problems, we propose a call drop rate estimation algorithm for the purpose of call admission control based on measured value at LNA(Low Noise Amplifier) ports of BTS(Base Transceiver Station) in real time. This method proposed in this paper estimates a quality of offered service in real time, reduce system loads and shorten time delay which is needed to determine the standard for call admission control. But it requires a additional 17W complexity which can measure received signal power in BTS and estimate call drop rate.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.3
• /
• pp.19-28
• /
• 2001

The purpose of this paper is to examine factors affecting user´s satisfaction in development of natural recreation forest(NRF) in order to answer the research question: What is the magnitude of factors affecting user´s satisfaction in development of NRF. After reviewing the literature, mechanism of outdoor recreation, and development factors in NRF, we constructed the conceptual framework and have formulated the hypothesis of this research. we have obtained data through a questionnaire, which surveyed 625 visitors at 10 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test, Pearson´s correlation analysis, and multiple linear regression method. We found that 1) all the development factors except recreational resources affecting user´s satisfaction have turned out to be statistically significant at one percent level. The direction of relationship between independent variable and dependent variable is the same as that of dependent variable. 2) in bivariate analysis, the relationships between user´s satisfaction and all the development factors are fairly high and statistically significant. The higher the value of development factors, the higher the degree of user´s satisfaction. 3 in multivariate analysis, such variables as the suitability of activities level of services, atmosphere, and facility have been statistically significant at one percent level, and 4) Their relative contribution of the suitability of various recreational activities, level of atmosphere, and service on dependent variable have been turned out to have 8.167, 4.889, 3.333, and 1.611 times more importance than that of the suitabity of recreational resources, respectively. The research results suggest that a guideline for the creation of marketable NFR and development of use-programs and recreational atmosphere be recommended in the planning and development process of NRF, and excessive investment on facilities is not desirable. The approach and analysis method adopted by this research is highly useful for an evaluation criterion of NRF and development of devices for increasing user´s satisfaction in NRF. It is recommended that more empirical study on individual factors affecting user´s satisfaction be performed in the future.

• Journal of Information Technology Services
• /
• v.19 no.2
• /
• pp.109-124
• /
• 2020

Facing the 4^th Industrial Revolution era, researches on artificial intelligence have become active and attempts have been made to apply machine learning in various fields. In the field of finance, Robo Advisor service, which analyze the market, make investment decisions and allocate assets instead of people, are rapidly expanding. The stock price prediction using the machine learning that has been carried out to date is mainly based on the prediction of the market index such as KOSPI, and utilizes technical data that is fundamental index or price derivative index using financial statement. However, most researches have proceeded without any explicit verification of the prediction rate of the learning data. In this study, we conducted an experiment to determine the degree of market prediction ability of basic indicators, technical indicators, and system risk indicators (AR) used in stock price prediction. First, we set the core parameters for each financial indicator and define the objective function reflecting the return and volatility. Then, an experiment was performed to extract the sample from the distribution of each parameter by the Markov chain Monte Carlo (MCMC) method and to find the optimum value to maximize the objective function. Since Robo Advisor is a commodity that trades financial instruments such as stocks and funds, it can not be utilized only by forecasting the market index. The sample for this experiment is data of 17 years of 1,500 stocks that have been listed in Korea for more than 5 years after listing. As a result of the experiment, it was possible to establish a meaningful trading strategy that exceeds the market return. This study can be utilized as a basis for the development of Robo Advisor products in that it includes a large proportion of listed stocks in Korea, rather than an experiment on a single index, and verifies market predictability of various financial indicators.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.05a
• /
• pp.695-698
• /
• 2005

최근 국외의 전력회사들은 미래 디지털 사회의 기반이 되는 신전력시스템을 구현하는데 필요한 핵심기술중의 하나로서 IT(Information Technology)기반 전력부가서비스 기술의 중요성에 대해 강조하고 있으며, 이를 위해 원격검침 데이터를 기반으로 하는 다양한 전력부가서비스를 개발하여 적용하고 있다. 한편 국내의 경우 원격검침 데이터는 전력요금 산출용도로 활용되고 있는 수준이다. 전력회사는 원격검침 데이터가 고객과의 관계에서 부가가치를 높일 수 있는 무한한 잠재력을 지닌 전략적인 자산으로 보고, 원격검침 데이터 가공 및 활용기술의 선진화를 통하여 전력회사와 전력소비자 모두에게 필요한 전력부가서비스의 적용이 필요하다. 본 논문에서는 국내 전력산업 환경에 적합한 새로운 전력부가서비스 적용방안으로 제안한 전력 에너지 컨설팅 서비스에 대해 소개하고자 한다. 본 논문에서 제안한 전력부가서비스의 적용은 전력소비자 측면에서는 요금절감 효과가 전력회사 측면에서는 부하 수요관리 및 투자비 절감 효과가 예상된다.