• The Journal of Information Systems
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• v.5
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• pp.383-409
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• 1996

This study has two research objectives related to end-user computing (EUC). One of the research objectives was to investigate the current status of EUC of Korean firms. Another research objective was to examine the relationship between individual differences of end-users and EUC success. Using survey data from 752 end-users of 23 firms, the current status of EUC and the relationship between individual differences of end-users and EUC success were investigated. The current status of EUC was examined from six perspectives : 1) what is the characteristics of EUC strategy of Korean firms, 2) what are the individual characteristics of end-users in Korean firms 3) what are the characteristics of tasks performed by end-users computer, 4) what are the application areas of EUC, 5) How end-users are satisfied with the support of firm, 6) what are system usage and satisfaction of end-users. It was also found that individual differences of end-users are related to EUC success. More specifically, it was shown that the male gender, younger age, higher level of education, higher rank and organizational tenure, higher math ability, thinking type of cognitive style, positive and optimistic attitudes toward computer, more experience with computer, more computer education and knowledge are individual differences variables associated with EUC success. The results of stepwise regression analysis suggested that the individual difference variables accounted for 14%, 25%, 39%, and 30% of the variances of four EUC success variables, satisfaction for outcome, satisfaction for ability, frequency of computer use, and the number of tasks, respectively. Theses empirical findings suggest that EUC managers should consider individual differences of end-users in managing EUC, such as education, training support, and human resource management, to maximize potential benefits of EUC.

• Journal of Korea Multimedia Society
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• v.2 no.3
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• pp.231-242
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• 1999

Generally, either caption-based search method or content-based search methods is used to retrieve video information. However, each search method has its limitations. Caption-based search is apt to lose consistency as for user's subjects, and content-based search is hard to extract general means. To enhance efficiency and correctness as for complementing each other, we propose the Integrated Video Data Model(IVDM) which integrates the two search methods, to device the model, we analyze video data and construct the structure of video information hierarchically. IVDM supports caption-based search as assigning meta-data by analyzing thematic-unit in the higher level, and also supports content-based search as extracting feature data by analyzing the content of video data in the lower level. We design Object-Oriented database schema of news video, based-on the IVDM. And we provide 4-type of queries and query processing algorithm to retrieve news video information.

• Journal of Broadcast Engineering
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• v.14 no.3
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• pp.280-287
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• 2009

An IPTV (Internet Protocol Television) technology is the new convergence technology of the telecommunication and broadcasting which provides various bidirectional TV services. To provide these services only to legal subscribers, mutual authentication between set-top box connected with TV set and the smart card owned by a subscriber is needed. In this paper, we propose an attribute-based mutual authentication scheme that only someone who is satisfied with some attributes, such as titles or departments, can access the contents provided by the IPTV service in an organization. We also show that the proposed scheme is secure. Our proposed scheme has a virtue that user can access various services, provided by an organization where he/she belongs to, according to their attributes with only one time registration. As far as we know, this is the first attribute-based authentication scheme which can be applied to any organizations in IPTV environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1239-1247
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• 2010

In this paper, we were researched decision problem called an optimal release policies after testing a software system in development phase and transferring it to the user. The applied model of release time exploited infinite failure non-homogeneous Poisson process This infinite failure non-homogeneous Poisson process is a model which reflects the possibility of introducing new faults when correcting or modifying the software. The intensity function used Gompertz, Preto and Log-logstic pattern which has the efficient various property. Thus, optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement becomes an optimal release policies. In a numerical example, after trend test applied and estimated the parameters using maximum likelihood estimation of inter-failure time data, estimated software optimal release time.

• Journal of Korean Library and Information Science Society
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• v.32 no.2
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• pp.59-91
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• 2001

United Nations Depository Library Systems is not yet well known to the Public. United Nations as an international organization founded on the basis of various cultures, ethnic groups and political & economical backgrounds, have complied all its policies and activities into various type of materials in written form from the beginning. These materials including laws, periodicals and monographs produced from UN\`s various activities have a great vale as library materials containing useful information. UN has distributed them throughout the designated libraries called UN Depository Libraries for the world users. So UN materials are available to users not only from the member countries but from the world. I the Republic of Korea several depository libraries have received a large quantity of UN materials since the 1990\`s. However, these materials have not been utilized well. Under thee circumstances, this study tries to present the ways to promote user\`s understanding of UN material and encourage them to use the valuable information more effectivity.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.287-296
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• 2008

The IEEE 802.11 wireless standard uses the carrier sense multiple access with collision avoidance (CSMA/CA) as its MAC protocol (during the distributed coordination function period). This protocol is an adaptation of the CSMA/CD of the wired networks. CSMA/CA mechanism cannot guarantee quality of service (QoS) required by the application because orits random access method. In this study, we propose a new MAC protocol that considers different types of traffic (e.g., voice and data) and for each traffic type different priority levels are assigned. To improve the QoS of IEEE 802.11 MAC protocols over a multi-channel CSMA/CA, we have developed a new admission policy for both voice and data traffics. This protocol can be performed in direct sequence spread spectrum (DSSS) or frequency hopping spread spectrum (FHSS). For voice traffic we reserve a channel, while for data traffic the access is random using a CSMA/CA mechanism, and in this case a selective reject and push-out mechanism is added to meet the quality of service required by data traffic. To study the performance of the proposed protocol and to show the benefits of our design, a mathematical model is built based on Markov chains. The system could be represented by a Markov chain which is difficult to solve as the state-space is too large. This is due to the resource management and user mobility. Thus, we propose to build an aggregated Markov chain with a smaller state-space that allows performance measures to be computed easily. We have used stochastic comparisons of Markov chains to prove that the proposed access protocol (with selective reject and push-out mechanisms) gives less loss rates of high priority connections (data and voices) than the traditional one (without admission policy and selective reject and push-out mechanisms). We give numerical results to confirm mathematical proofs.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.311-324
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• 1997

General citizens can be a valuable resource for various types of environmental monitoring when they are well-trained and managed. Successful use of volunteer monitors depends on understanding that citizens are partners sharing expanded roles as the guardians of their local environment. Citizen volunteer monitoring programs are developed for three reasons: 1) to supplement environmental data collected by professional staffs in governmental agencies and scientific institutions; 2) to educate the public about local environmental problems; 3) to build a constituency of citizen to practice sound environmental management at a local level and build public support for environmental protection. All three goals can be achieved with a well-organized program which provides useful and credible data. Initial step in planning a successful volunteer monitoring project is to clearly identify the use to be made of the data. Technical advice from the identified potential user groups should be convened early in the planning stage to refine the program objectives and determine if volunteers can provide the level of expertise required. Data users must have confidence in the representativeness, consistency, and accuracy of data collected by volunteers. Effective quality assurance and quality control(QA/QC) procedures are essential to ensure the utility of environmental monitoring data. Volunteers must be trained in advance to carry out specific environmental monitoring tasks. Another components of successful volunteer monitoring programs is to give the volunteers praise and feedback as well as to encourage experienced volunteers to impose increased responsibilities. The increase of volunteer monitoring programs in Korea will play a major role in developing a participatory system in which the people are "empowered" to make decisions and make a difference.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.229-234
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• 2013

The purpose of this study is to develop a lighting apparatus of the illuminance and color temperature to maximize the ability of the optimal combination of light sources that can be controlled efficiently control device. Finding people comfortable feeling for indoor lighting that can be used in a variety of color temperature illumination area by combining light sensitivity can be realized. Lighting apparatus for fluorescent lamps with different color temperature of 2000K and 8000K, and by varying the quantity of each of the fluorescent lamps, the illuminance of lighting equipment and color temperature through optical simulations were evaluated. By infrared remote control receiver, divided into 5 types of relaxation, conversation, meeting, hospitality, arts and the lighting environment you want to transfer the PC0 ~ PC4 through the parallel port on the mode selected by the user at the receiving end the DC voltage output. EEFL inverter input DC voltage and the DC input voltage, depending on the level of EEFL dimming value (illuminance and color temperature) lighting environment you want to create change while using a PIR sensor EEFL automatically turn off if people do not have was developed so that the power consumption so you can save.

• Journal of the Korea Convergence Society
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• v.1 no.1
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• pp.23-29
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• 2010

The various kinds of application is distributed for the Smart phone user recently. There is the advantage that the open source application on Android operating system based Smart phone supports a multi tasking service. Layar, Wikitude, and Sherpa and the other applications using the GPS location information like an a2b etc. were developed in the Smart phone environment. However, the existing Cell-ID based location information can be directly collected by the mobile ISP unit which the mobile carrier installs, the personal privacy problem occurs. Therefore, the personal location information is possible to be exposed publicly without any access control procedure. Therefore, in this research, the self-control mechanism on the GPS location information at the Smart phone is designed and presented. Through this, it is possible to develop diverse applications providing enhanced access control and GPS location management on the Android based Smart Phone.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1241-1250
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• 2002

The communication between Ship and Land have bad communication environment and high cost comparing with land situation. In case of data communication for I-mail, the primary used speed is from 4800 bps to 9600bps. even this low speed user has difficulty to use data communication because of high cost. and this kind of data communication software is all imported from foreign country. In this paper we designed and implemented this communication server and client using Inmarsat A/B/miniM/M4/GAN(F77) by benchmarking of foreign product like Netverk, Marinet, Amosmail. the focus of this product is like next 1) communication cost down 2) Link between Ship Application and Land Office Application 3) Convenient of usage in Ship 4) perfect management of message to from ship.