• Journal of ILASS-Korea
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• v.19 no.4
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• pp.188-196
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• 2014

The spray and combustion characteristics of n-dodecane fuel were investigated in a CVCC (constant volume combustion chamber). The selection of ambient conditions for the spray followed ECN (engine combustion network) guidelines, which simulates the ambient condition of diesel engines at start of fuel injection. ECN is a collaboration network whose main objective is to establish an internet library of well-documented experiments that are appropriate for model validation and the advancement of scientific understanding of combustion at conditions specific to engines. Therefore repeatability of the experiments with high accuracy was important. The ambient temperature was varied from 750 to 930 K while the density was fixed at around $23kg/m^3$. The injection pressure of the fuel was varied from 500 to 1500 bar. The spray was injected in both non-reacting ($O_2$ concentration of 0%) and reacting conditions ($O_2$ concentration of 15%) to examine the spray and the combustion characteristics. Direct imaging with Mie Scattering was used to obtain the liquid penetration length. Shadowgraph was implemented to observe vapor length and lift-off length at non-reacting and reacting conditions, respectively. Pressure data was analyzed to determine the ignition delay with respect to the spray and ambient conditions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.371-384
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• 2001

In these days, it is continuously increased to the intrusion of system in internet environment. The methods of intrusion detection can be largely classified into anomaly detection and misuse detection. The former uses statistical methods, features selection method in order to detect intrusion, the latter uses conditional probability, expert system, state transition analysis, pattern matching. The existing studies for IDS(intrusion detection system) use combined methods. In this paper, we propose a new intrusion detection algorithm combined both state transition analysis and association mining techniques. For the intrusion detection, the first step is generated state table for transmitted commands through the network. This method is similar to the existing state transition analysis. The next step is decided yes or no for intrusion using the association mining technique. According to this processing steps, we present the automated generation algorithm of the penetration scenarios.

• 한국벤처창업학회:학술대회논문집
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• 2018.11a
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• pp.277-281
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• 2018

Information system has been at center of economic development in several developed countries, and as Africa envision to improve its global economic competitiveness it is important to assess penetration rate the digital divide and catch-up effect over the years. This paper examined whether there exists digital divide and if so, is it narrowing over time and whether the ICT is converging with time in the African countries. Three technologies namely mobile-cellular, internet and fixed broadband were used to measure the digital divide and the catch-up effect. Gamma and sigma convergence methodology together with averaged penetration ratios were used to assess the cross-country performance of each technology. This study confirms both the narrowing of digital divide and convergence of ICT in all three technologies for both total group and subgroups. The digital gap was narrowing over time and the low-income countries were catching up faster to the middle-income countries in all three technologies. However, there are marked differences exhibited in the speed of narrowing digital divide and the speed of convergence between the total groups and the subgroups of countries. Some policy implications were discussed in the conclusion and they can be utilized in designing developmental ICT policies in each technology case for individual countries.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.1003-1008
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• 2017

The Internet of Things has attracted considerable research attention in recent years. In order for the new IoT technology to be widely used, the reliability and protection of information is required. IoT systems are very vulnerable to physical security due to their easy accessibility. Along with the development of SoC technology, many operating systems have been developed and many new operating systems have been introduced. In this paper, we describe the vulnerability analysis results for operating systems running on the ARMv7 Thumb Architecture hardware platform. For the recently introduced "Windows 10 IoT Core" operating system, I implemented the Zero-Day Attack by implanting the penetration code developed through the research into a specific IoT system. The virus detection test for the resulting penetration code was validated by referral to the "virustotal" site.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.217-226
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• 2018

Since the sides of a vehicle are designed asymmetrically unlike its front or rear, the degree of deformation of the car body greatly differs depending on the site of collision if a broadside collision takes place. When elastic deformation and plastic deformation occur in the car body occur due to a collision, the kinetic energy is absorbed into the body, and the momentum decreases. Generally, an analysis of traffic accidents analyzes the vehicle's behavior after a collision by the law of momentum conservation and corrects the error of the amount of energy absorption due to the deformation of the car body, applying a restitution coefficient. This study interpreted a finite element vehicle model applying the structure of the car body and the material properties of each part with LS-DYNA, analyzed the result and drew the restitution coefficient and the depth of penetration according to the contact area of the vehicle in a broadside collision between an SUV and a passenger car. When the finally calculated restitution coefficient and depth of penetration were applied to the examples of the actual traffic accidents, there was an effect on the improvement of the error in the result. It was found that when the initial input value, drawn using the finite element analysis model, it had a higher reliability of the interpretation than that of the existing analysis techniques.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.741-744
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• 2006

The e-commerce introduction at the Internet in base accept the renovation dimension from the organised side because of follow of the business in order to the big change. So when I considering the e-commerce introducing the problem easy to originate from the efficiency and expectation without radical preparation. Each commodities over the dimension of Internet information search it is using the various transaction of service as a matter of bank, securities, education, game that many business on the alternation of e-commerce and commerce tool the essentiality. Therefore the transactions at the Internet e-commerce under hold specific gravity and rule in the future with the propection increase the interest concern about the security skill. A study on this paper presentation through the planning method about the analysis on the objective which e-commerce follow the inflection of efficiency strategy and induction the plan on the penetration's revitalization about Internet e-commerce.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.111-124
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• 2015

The economic growth in China takes the step of the Internet/Mobile revolution together. The high internet penetration provided the opportunity to increase the e-commerce market with fast speed. However, due to imbalance of the growth speed and preparation, the problems on various infrastructures and regulations were generated. Therefore, this study investigateed the current status of e-commerce market and sub-categories. This study also discussed about the problem of e-commerce logistics system, consumer protection, R&D investment, and human resources and provided the considerations for the future improvement. Finally, this study diagnosed the mobile payment and internet finance market and new e-commerce tax regulation, and then suggested institutional implications for the international standardization. This study is meaningful to provide the first implication to the Korean exporters after Chinese government had announced market open strategy for the 5 year e-commerce development plan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5527-5545
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• 2019

Through-wall ultra-wide band (UWB) radar has been considered as one of the preferred and non-contact technologies for the targets detection owing to the better time resolution and stronger penetration. The high time resolution is a result of a larger of bandwidth of the employed UWB pulses from the radar system, which is a useful tool to separate multiple targets in complex environment. The article emphasised on human subject localization and detection. Human subject usually can be detected via extracting the weak respiratory signals of human subjects remotely. Meanwhile, the range between the detection object and radar is also acquired from the 2D range-frequency matrix. However, it is a challenging task to extract human respiratory signals owing to the low signal to clutter ratio. To improve the feasibility of human respiratory signals detection, a new method is developed via analysing the standard deviation based kurtosis of the collected pulses, which are modulated by human respiratory movements in slow time. The range between radar and the detection target is estimated using joint time-frequency analysis (JTFA) of the analysed characteristics, which provides a novel preliminary signature for life detection. The breathing rates are obtained using the proposed accumulation method in time and frequency domain, respectively. The proposed method is validated and proved numerically and experimentally.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.267-272
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• 2012

IT convergence, social media, and the companies' customer service industry advancement, data collection activities, explosion of multimedia content with increased smartphone penetration, SNS activation networks to expand the pool of things, 10 years ago, the amount of data eunneun evenly across industries, EDW (Enterprisehad increased the demand for the Data Warehouse).Recent proliferation of SNS users and applied research background with Big Data as a new study is proposed to proceed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.1
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• pp.27-34
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• 2018

Various messages generated in vehicles are transmitted based on the wireless telecommunication which is a core technology of vehicle to everything (V2X). However, the hackers attack them upon penetration to the system and network to cause the generation of users' inconveniences for vehicular communication. Moreover, huge damage could be occurred in terms of physical and materialistic areas if the users in the vehicles were attacked in the communication environment. Therefore, this study was to design the safe communication protocol using hash tree technique in the V2X environments. Using hash tree technique, processes of issuing certificate and registration and communication protocol were designed, and safety analysis was performed on the attacking technique which is occurred in the existing vehicles. Approximately 62% of decrease in the capacity analysis was found upon comparative analysis of telecommunication processes with the system to issue the certificate which is used in the existing vehicles.