• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.269-277
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• 1996

This paper has been presented a design of a POCSAG decoder in RT-level VHDL and implemented in a FPGA chip, and tested. In a single clock of 76.8KHz, the decoder receives all the data of the rate of 512/1200/2400bps and has maximum 2-own frames for service enhancement. To improve decoder performance, the decoder uses a preamble detection cosidering 9% frequency tolerance, a SCW detction and a ICW detection at each 4 bit. The decoder also corrects a address data and a message data up to 2 bits and proposes the PF (preamble frequency) error for saving battery. The decoder increases a battery life owing to turn off RF circuits when the preamble signal is detected with nises. The chip has been designed in RT-level VHdL, synthesized into logic gates using power view$^{TM}$ of viewlogic software. The chip has been implemented in an ALTERA EPF81188GC232-3 FPGA chip with 98% usability, and fully tested in shield room and field room. The chip has been proved that the wrong detection numbers of preamble of noises are significantly reduced in the pager system using PDI 2400 through the real field test. The receiving performance is improved by 20% of aaverage, compared with other existing systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2C
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• pp.333-341
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• 2004

Along with the innovative enhancement of Internet technology and the emergency of distributed systems extended from client-server computing, it becomes indispensible and necessary to integrate and interconnect old legacy systems. Since building a distributed system requires consistency of integration, the proper reuse of incumbent systems is critical to successful integration of current systems to distributed ones. CORBA(Common Object Request Broker Architecture) and object wrapping technique can provide middleware solutions that extend the applications of a legacy system with little modification to the application level while keeping client consistency of standard interface. By using these techniques for system integration it is easier and faster to extend services on application development to distributed environments. We propose a model on object wrapping system that can manage, integrate, and separate the functions delivered from CORBA. We apply the object wrapping model specifically to integration of security system interfaces and also perform a test to verify the usability and the efficiency of our model.

• Spatial Information Research
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• v.15 no.3
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• pp.251-266
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• 2007

Even on the point that the 3rd National GIS project is being executed following the completion of the 1st and 2nd, the National GIS utilization is still very low. It is well reasonable to anticipate that the utilization will grow much higher, as the national spatial data infrastructure had been almost equipped through the 1st and 2nd project periods. Facing the ubiquitous era, in particular, as the national-level GIS demand is to increase to a great extent, pre-established GIS application scope will become much wider, too. In preparation for these, the current study focused on the National GIS utilization system by reviewing on the execution procedures to evaluate the outcomes. For the actual administration procedures, to note, the National GIS utilization statuses by local municipalities were investigated in depth. And the barriers for the National GIS utilization enhancement were analyzed to look for feasible solutions. The results suggested were aimed to contribute to the amendment of the 3rd Master Plan, and to be used as part of the basic data for the establishment of the 4th Master Plan for the National GIS.

• Journal of the Korean Society for Railway
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• v.17 no.6
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• pp.402-409
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• 2014

Wireless local area network (WLAN) is a widely used wireless access method due to its easy usability and excellent performance. However, its performance degrades significantly as the number of users increases. In busy train stations, where the number of WLAN users are large and, more importantly the number of simultaneous packet transmission attempts is extremely large due to the time synchronization upon train arrival, the packet transmission delay problem is very severe and almost impossible for WLAN stations to initiate communication with WLAN networks. In this paper, a novel distributed WLAN access scheme for efficient WLAN communication in busy train stations is proposed. Using the proposed scheme, WLAN access delay can be significantly reduced under highly congested traffic environments. Therefore, a significant performance enhancement for the WLAN performance used in the Communication Based Train Control (CBTC) can be achieved.

• Asia pacific journal of information systems
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• v.18 no.4
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• pp.105-130
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• 2008

Consumers of e-learning market differ from those of other markets in that they are replaced in a specific time scale. For example, e-learning contents aimed at highschool senior students cannot be consumed by a specific consumer over the designated period of time. Hence e-learning service providers need to attract new groups of students every year. Due to lack of information on products designed for continuously emerging consumers, the consumers face difficulties in making rational decisions in a short time period. Increased uncertainty of product purchase leads customers to herding behaviors to obtain information of the product from others and imitate them. Taking into consideration of these features of e-learning market, this study will focus on the online herding behavior in purchasing e-learning contents. There is no definite concept for e-learning. However, it is being discussed in a wide range of perspectives from educational engineering to management to e-business etc. Based upon the existing studies, we identify two main view-points regarding e-learning. The first defines e-learning as a concept that includes existing terminologies, such as CBT (Computer Based Training), WBT (Web Based Training), and IBT (Internet Based Training). In this view, e-learning utilizes IT in order to support professors and a part of or entire education systems. In the second perspective, e-learning is defined as the usage of Internet technology to deliver diverse intelligence and achievement enhancing solutions. In other words, only the educations that are done through the Internet and network can be classified as e-learning. We take the second definition of e-learning for our working definition. The main goal of this study is to investigate what factors affect consumer intention to purchase e-learning contents and to identify the differential impact of the factors between consumers with purchase experience and those without the experience. To accomplish the goal of this study, it focuses on herding behavior and perceived usefulness as antecedents to behavioral intention. The proposed research model in the study extends the Technology Acceptance Model by adding herding behavior and usability to take into account the unique characteristics of e-learning content market and e-learning systems use, respectively. The current study also includes consumer experience with e-learning content purchase because the previous experience is believed to affect purchasing intention when consumers buy experience goods or services. Previous studies on e-learning did not consider the characteristics of e-learning contents market and the differential impact of consumer experience on the relationship between the antecedents and behavioral intention, which is the target of this study. This study employs a survey method to empirically test the proposed research model. A survey questionnaire was developed and distributed to 629 informants. 528 responses were collected, which consist of potential customer group (n = 133) and experienced customer group (n = 395). The data were analyzed using PLS method, a structural equation modeling method. Overall, both herding behavior and perceived usefulness influence consumer intention to purchase e-learning contents. In detail, in the case of potential customer group, herding behavior has stronger effect on purchase intention than does perceived usefulness. However, in the case of shopping-experienced customer group, perceived usefulness has stronger effect than does herding behavior. In sum, the results of the analysis show that with regard to purchasing experience, perceived usefulness and herding behavior had differential effects upon the purchase of e-learning contents. As a follow-up analysis, the interaction effects of the number of purchase transaction and herding behavior/perceived usefulness on purchase intention were investigated. The results show that there are no interaction effects. This study contributes to the literature in a couple of ways. From a theoretical perspective, this study examined and showed evidence that the characteristics of e-learning market such as continuous renewal of consumers and thus high uncertainty and individual experiences are important factors to be considered when the purchase intention of e-learning content is studied. This study can be used as a basis for future studies on e-learning success. From a practical perspective, this study provides several important implications on what types of marketing strategies e-learning companies need to build. The bottom lines of these strategies include target group attraction, word-of-mouth management, enhancement of web site usability quality, etc. The limitations of this study are also discussed for future studies.

• Journal of Distribution Science
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• v.12 no.4
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• pp.41-46
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• 2014

Purpose - This study focused on providing strategic findings that make significant sense for companies that are looking for a future outsourcing strategy. The study analyzes the results of outsourcing in the information logistics systems field and verifies the results through experimental study of the performance delivered by logistics outsourcing types. Research design, data, and methodology - The study sample was assembled based on a random sampling method used to extract the initial 451 companies from a list of Korean distributors, wholesalers, and retailers. Following that sample process, 423 companies were confirmed by verifying their e-mail address and contacts (telephone and fax numbers), and were selected as initial research subjects. We reduced that number to 331 companies for the survey sample through telephone interviews in advance with the 423 companies that were targeted, in order to verify whether they are in the field of outsourcing of information logistics systems. The period of the survey extended from November 10, 2013 to January 10, 2014. The number of collected surveys totaled 181. We reviewed the contents of the survey responses, and reduced the number of research subjects to 175. In this study, we used a standard analysis to investigate whether there is a difference in distribution results based on different types of outsourcing information in the logistics system field and, through T-verification, we investigated whether the difference between distribution results in each group resulting from that standard analysis is statistically significant. Results - These results show that there is a difference in distribution outcome, based upon type of distribution outsourcing. In addition, we determined that they are meaningful results by confirming that, for usability and to improve the capabilities of a third-party logistics service supplier, both the choice of reasonable outsourcing types and the enhancement of various types of alliances are very important success factors. Taken together these study results, with a goal of enhancing the distribution capabilities of a Korean distributor, can be implemented to enhance management results achievable by supplying an information logistics system in the form of strategic outsourcing rather than in the form of simple outsourcing. In addition, the outcomes of logistics distributors in Korea that are using outsourcing in the logistics information systems field show high performance results in commercial endeavors in the following order: competitive, pre-competitive, non-competitive, and pro-competitive. Conclusions - This study focused on providing strategic findings. However, in the case of outsourcing in the field of information logistics systems of Korean distributors, there has been a focus on simple outsourcing rather than on strategic outsourcing; furthermore, there has been a concentration on non-competitive forms instead of pro-competitive forms, which could achieve better distribution results. This discussion is presented in more detail in the analysis results of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2818-2826
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• 2010

This research was conducted to develop a model appropriate for the measurement of information quality of UCC service site. The evaluation factors that reflect more improvement of the information utilization capability were verified. Enhancement of information utilization capability can control greater amount of information among the users and site companies, and among users. Therefore, Wikipedia, for example, provides a Web 2.0 based information quality that is more advanced than Web 1.0 by allowing effective control of information among the users. This type of information quality presents 'information reliability' and 'information stability' as evaluation factors added to the factors such as 'information sufficiency' and 'information usability.' Information reliability and information stability are essential factors that need to conduct an evaluation in the Web 2.0 environment that can distribute greater number of information in the environment where all the users serve as participants. Moreover, 'interesting information' and 'originality of information' suggests that information itself should include the attributes that can attract the attention of users, due to the nature of the Attention Economics, which points out one of the Web 2.0 phenomenon that the number of information consumers is smaller than that of information suppliers.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.353-358
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• 2014

This study was conducted to analyze the patient's exposed dose targeting the patients who had acute ischemic stroke symptoms and CT brain perfusion scan, by comparing fixed time technique and bolus tracking technique which was provided by the manufacturer and to identify the Time graph to implement the usability of contrast medium's tracking technique the best contrast enhancement intervals. $CTDI_{VOL}$ of PCT in patient appeared to be 431.72mGy in fixed scan delay protocol, whereas 323.61mGy in Bolus tracking technique. The value of DLP appeared to be $1243.47mGy{\cdot}cm$ in fixed scan delay protocol, whereas $932mGy{\cdot}cm$ in Bolus tracking technique. Time graph appeared to be various in fixed scan delay protocol, whereas the optimal time graph could be obtained in Bolus tracking. The exposure dose could be reduced by 25% applying Bolus tracking technique when taking brain perfusion CT scan.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.466-476
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• 2019

This study suggested a way to compose a flexible environment capable of meeting the needs of various users from the aged people to challenged people, and ordinary people by applying the concept of universal design. The purpose of this study was to develop a more convenient environment by deriving the best size and color for each subject and constructing a detailed design platform for each module. For this, the concept of universal design as well as the current bathroom designs were examined and various users were analyzed prior to developing the design. A virtual environment was prepared based on the results and its usability was evaluated in two phases with various users including the aged people, challenged people, and ordinary people. As a result, it received quite a favorable evaluation from users, over 90 out of 100 in average, which can be regarded as a proof that it is differentiated from existing bathrooms. This study may lead to the change in the paradigm of bathroom in residential space, development of safer and comfortable domestic environment, and the enhancement of the quality of healthy life through the development of a design platform for each module that provides new experiences to various users. It is hoped that these modular systems are continuously studied not only for bathrooms but also for various residential spaces where people can stay.

• Science of Emotion and Sensibility
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• v.25 no.4
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• pp.45-52
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• 2022

Recently, interest in and demand for sensors that recognize physical activity and their products are increasing. In particular, the development of wearable materials that are flexible, stretchable, and able to detect the user's biological signals is drawing attention. In this study, an experiment was conducted to improve the dip-coating efficiency of a single-walled carbon nanotube dispersion solution after fine holes were made in a hydrophobic material with a micro needle. In this study, dip-coating was performed with a material that was not penetrated, and comparative analysis was performed. The electrical conductivity of the sensor was measured when the sensor was stretched using a strain universal testing machine (Dacell Co. Ltd., Seoul, Korea) and a multimeter (Keysight Technologies, Santa Rosa, CA, USA) was used to measure resistance. It was found that the electrical conductivity of a sensor that was subjected to needling was at least 16 times better than that of a sensor that was not. In addition, the gauge factor was excellent, relative to the initial resistance of the sensor, so good performance as a sensor could be confirmed. Here, the dip-coating efficiency of hydrophobic materials, which have superior physical properties to hydrophilic materials but are not suitable due to their high surface tension, can be adopted to more effectively detect body movements and manufacture sensors with excellent durability and usability.