• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.822-831
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• 2008

This paper examines the theoretical and empirical technology diffusion processes to understand the Korean success in the internet access service markets. In order to do this, first, we propose an integrated demand diffusion model in terms of competition of inter-and intra-technologies and market structure as represented by the number of operators in the market. Second, by using the proposed model, we analyze the dynamic diffusion processes of Korean internet access services such as Narrow-band technology including Dial modem vs. Broad-band technology including ISDN, xDSL and Cable modem. The competition of inter-and intra-technologies as well as the extent of market competition has made a positive effect on the diffusion patterns of internet access demand. And also we propose, based on the proposed model and its empirical results, several implications for diffusion strategies and policies in the future of ICT market in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8B
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• pp.947-953
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• 2011

These days, a consistent and fatal attack attribute toward a database has proportionally evolved in the similar development form to that of security policy. Because of access control-based defensive techniques regarding information created in closed networks and attacks on a limited access pathway, cases of infringement of many systems and databases based on accumulated and learned attack patterns from the past are increasing. Therefore, the paper aims to separate attack information by its types based on a virtual infringement pattern system loaded with dualistic VM in order to ensure stability to limited certification and authority to access, to propose a system that blocks infringement through the intensive management of infringement pattern concerning attack networks, and to improve the mechanism for implementing a test that defends the final database, the optimal defensive techniques, and the security policies, through research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1898-1903
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• 2021

Recently, the need to be wary of internal access such as internal access as well as external attackers' access to work has increased due to network expansion, cloud infrastructure expansion, and changes in working patterns due to COVID-19 situations. For this reason, a new network security model called Zero Trust is drawing attention. Zero Trust has a key principle that a trusted network does not exist, and in order to be allowed access, it must be authenticated first, and data resources can only be accessed by authenticated users and authenticated devices. In this paper, we will explain these zero trust and zero trust architectures and examine new security application strategies applicable to various companies using zero trust and the process of building a new security system based on the zero trust architecture model.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.185-192
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• 2024

The aviation has improved safety through technological innovation and strengthened flight safety through safety regulations and supervision by aviation authorities. As the industry's safety approach has evolved into a systematic approach to the aircraft system, airlines have established a safety management system. Technical defects or abnormal data in an aircraft can be warning signs that could lead to an accident, and the risk of an accident can be reduced by identifying and responding to these signs early. Therefore, management of abnormal warning signs is an essential element in promoting data-based decision-making and enhancing the operational efficiency and safety level of airlines. In this study, we present a model to statistically analyze quick access recorder (QAR) flight data in the preliminary analysis stage to analyze the patterns and causes of crab landing events that can lead to runway departures when landing an aircraft, and provide a precursor to a landing event. We aim to identify signs and causes and contribute to increasing the efficiency of safety management.

• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.63-69
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• 2020

In this paper, we propose an indoor positioning technique using the landmark based on relative Access Point (AP) signal strengths. The absolute values of AP signals are used to conventional indoor positioning technologies, but they may be different because of the difference of the measuring device, the measuring environment, and the timing of the measurements. However, we found the fact that the flow of the AP's RSSI in certain places shows almost constant patterns. Based on theses characteristics, we identify the relative strength between the APs and store the certain places as landmarks where they show certain patterns. Once the deployment of the landmark map is complete, system calculate position of user using the IMU sensor of smartphone and calibrate it with stored landmarks. Our system shows 75.2% improvement over technology that used only sensors, and 39.6% improvement over technology that used landmarks that were selected with absolute values.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2177-2184
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• 2012

A different and effective method for indoor positioning system is needed and increased it's importance compare to the outdoor GPS based method. The FingerPrint positioning method is known as a superior method in indoor positioning system that maintains signal strength patterns for RPs(Reference Points) in database and compare the DB with the measured real-time signals on the mobile device. FingerPrint positioning method is necessary to establish an accurate database, but errors can occur by several factors. In this paper, we analyze the signal patterns of each terminal in accordance with connection state of access point and trace that the error in accordance with connection state of access point can be an important error in FingerPrint DB configuration through an experimental case study.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2245-2252
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• 1999

Since DSM provides a user a simple shared memory abstraction, the user does not have to be concerned with data movement between hosts. Each node in DSM systems has processor, memory, and connection to a network. Memory is divided into pages, and a page can have multiple copies in different nodes. To maintain data consistency between nodes, two conventional protocols are used : write-update protocol and invalidate protocol. The performance of these protocols depends on the system parameters and the memory access patterns. for adapting to memory access patterns, competitive update protocol updates those copies of a page that are expected to be used in the near future, while selectively invalidating other copies. We present weighted competitive update protocols that consider different communication bandwidth for each connection a of two nodes. Test result by simulation show that the weighted competitive update protocol improves performance.

• Korean Journal of Optics and Photonics
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• v.18 no.1
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• pp.74-78
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• 2007

We report theoretical and experimental results for application of transmittance-controlled photomask technology to ArF lithography. The transmittance-controlled photomask technology is thought to be a promising technique fo critical dimension (CD) uniformity correction on a wafer by use of phase patterns on the backside of a photomask. We could theoretically reproduce experimental results for illumination intensity drop with respect to the variation of backside phase patterns by considering light propagation from the backside to the front side of a photomask at the ArF lithography wavelength. We applied the transmittance-controlled photomask technology to ArF lithography for a critical layer of DRAM (Dynamic Random Access Memory) having a 110-nm design rule and found that the in-field CD uniformity value was improved from 13.8 nm to 9.7 nm in $3{\sigma}$.

• Journal of Korea Multimedia Society
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• v.9 no.1
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• pp.101-108
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• 2006

Developing a network game that is serviced on the internet requires a lot of work, time and manpower. Therefore, it is important to design a game in such a way so that existing design codes could be used. The database for the multi-player network game is accessed from many clients. To manage the resource effectively, it is required to design the APIs to be minimized the database access and to be dealt with the related data efficiently. For this, it is needed to apply the object-oriented design for the related software modules. In the paper, we propose the design patterns of GoF to implement the APIs thatis needed to deal with the database resource. The database design through the analysis of some game's GUI has the advantage to create the optimized schema set more quickly, because it minimize the review step and the modification step of the database design generally. In addition, we apply to the design patterns of GoF for the APIs design of the server-side database. These reduce the times of the program call between the game server and the database server. These also make easily the maintenance for the already developed APIs, and it makes easily the addition of new APIs.

• Research in Community and Public Health Nursing
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• v.12 no.1
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• pp.269-277
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• 2001

Purpose. The purpose of this study was to compare the total lifestyle patterns. of allergy and non-allergy group. Method. The study was carried out to access the lifestyle patterns such as food intake, smoking, alcohol intake and exercise habits by questionnairing the no allergy people and 205 non-allergy people living in Seoul area. Results. 1. The proportion of eating stimulatory food materials-mainly hot and salty-of allergy group were significantly higher than those of non-allergy group. 2. In allergy group, the proportion of meat intake was significantly higher than that of non-allergy. 3. In allergy group, exercise habit was higher than that of non-allergy, but not significant. 4. In allergy group, smoking was lower than that of non-allergy, but not significant. 5. In allergy group, alcohol intake was lower than that of non-allergy, but not significant. Conclusion. Lifestyle patterens such as food intake(salt and meat) were significantly different by prevalence of allergy and allergy type, which suggested that lifestyle patterns of allergy people need to be studied to develop preventive stratagies for allergic reaction.