• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.267-279
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• 2017

This study emulated unscheduled phishing e-mails over a long period of time by imitating the manner in which external hackers attacked a group of employees in a company. We then measured and analyzed the recipient's ability to identify and respond to phishing e-mails as training progressed. In addition, we analyzed the changes in participants' response behavior when changing the external control condition between the training. As a result of the analysis, it was confirmed that the training duration had a positive (+) relationship with the employees' ability to identify phishing e-mails and the infection rate, and more employees read emails and infected with phishing attacks using social issues and seasonal events. It was also confirmed that reinforcement of internal control policy on infected persons affects positively (+) on the phishing attack response behavior of employees. Based on these results, we would like to suggest the right training method for each organization to enhance the ability of employees to cope with phishing attacks.

• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.41-50
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• 2003

We tested the capability of the pleasure and arousal dimension-based facial expression synthesis system and proposed the most effective interface for it. First, we tried to confirm the adequateness of the dimensional model as a basic structure of the internal states for the system. Fer it, subjects compared the 17 facial expressions on the two axes. The results validated the fundamental hypothesis of the system. Second, we chose 21 representative expressions from the system to test its performance and had subjects rate their similarities. We analyzed these data using multidimensional scaling methods and these results verified the system's reliability. Third, we compared the efficiencies of two interfaces -coordinate values and slide bars- to find the most suitable interface for the system. Subjects synthesise 25 facial expressions with each interface of it. The results showed that the visualization of two dimensional values into Cartesian coordinate is more stable as an input display of facial expression synthesis system based on dimensions.

• Journal of Technology Innovation
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• v.8 no.2
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• pp.19-65
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• 2000

This study analyzes the development of technological infrastructure(TI) and technological infrastructure policy(TIP) to enhance the technological capabilities of small and mid-sized manufacturing enterprises(SMEs) in the U.S. and Korea in terms of the technological system(TS) concept, which is composed of technological infrastructure, industrial organization, and institutional infrastructure. In order to analyze the internal dynamics of the system, such as incentive mechanisms, the interaction among economic actors, and the policy implementation process, we compare the MEP(Manufacturing Extension Partnership) system of the U.S. and the Joong-Jin-Gong system of Korea. Among many similarities, contrasts, and insights from each country's effort to construct TI and TS, the main findings are as follows. (1) Both the MEP system and the Joong-Jin-Cong system are TI-led or government-led type TS. However, the nation-wide picture is different: in the U.S., most TSs including the MEP system., are classified as TI-led type; in Korea, many TI-assisted or private sector-led TSs have been developed since the early 1960s. (2) the MEP system, as a representative case of the U.S., is less stable than the Joong-Jin-Gong system of Korea in terms of financing and political cycle. (3) The MEP system is a more complex and cooperative network than the Joong-Jin-Gong system. NIST, as a critical mass, generates the system, bridges various institutions, and influences the development of the system by providing funding. (4) Regarding TI components, TSs in both countries focus on utilizing off-the-shelf technologies rather than advanced technologies. However, the direction of movement is different: in the U.S., TSs have come to emphasize existing technologies to counterbalance an innovation system that has been highly focused toward new technologies; in Korea, TSs have been moving from focusing on a higher diffusion rate of imported process technologies to stressing new technology development. (5) Personnel and staffing, embodying technological capability, is an important concern in both countries. But the human capital infrastructure of the U.S. system is more efficient and industry-oriented than that of the Korean system due to a more flexible labor market. (6) While the U.S. has a strong tradition of state and local autonomy in constructing TI and TS to fit SMEs's specific need, Korea has a centralized and bureaucratically-led policy implementation process.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.902-909
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• 2009

With various reservoirs, dams and reduction of water velocity in downstream, rivers in Korea often have characteristics of accumulation of pollutants. Therefore, the main focus of water quality modeling in Korea needs to be shifted from DO to algae and organic matter. Moreover the structures of water quality models should be modified to have capability of simulating BOD which is a key factor of total water pollution load management in Korea as laboratory experiment BOD (Bottle $BOD_5$). In the SWAT model which is one of the widely used water quality models in Korea, the channel water quality module is using main algorithm of the QUAL2E model which has limitations in simulating algae, organic matter and Bottle BOD5 etc. To overcome this hindrance, in this study, the improved channel water quality module of the SWAT model (Q-SWAT) was proposed by linking the algorithms of the QUAL-NIER model which was developed based on the QUAL2E model to the SWAT model. The algorithms estimating the increase of internal organic matter by fractionization algal metabolism process and calculating Bottle $BOD_5$ were added and the results of proposed model were compared to those of the original SWAT model. The results of comparison test are showing that more accurate BOD values can be obtained with the Q-SWAT model and it is anticipated that the Q-SWAT model can be used as an effective tool of decision support through the water quality simulation and long term pollution source analysis.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.153-158
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• 1998

Since the mid-1990′s, researches on 3D GIS have been regarded as one of main issues both in the academic sites and commercial vendors; recently, some prototyped systems or the first versioned software systems of commercial basis are being reported and released. Unlike conventional 2D GIS, which consists in intelligent structured GIS or desktop GIS, every 3D GIS has its own distinguished features according to data structure-supporting capability, GIS-styled functionality, external database accessibility, interfacing extents with 2D GIS, 3D visualization/texture mapping ability, and so forth. In this study, technical aspects related to system development, SERI-Web3D GIS ver. 1.2, are explained. Main features in this revised 3D GIS can be summarized: 2-tier system model(client-server), VGFF(Virtual GIS File Format), internal GIS import, Feature manager(zoning, layering, visualization evironment), Scene manager(manage 3D geographic world), Scene editor, Spatial analyzer(Intersect, Buffering, Network analysis), VRML exporter. While, most other 3D GISes or cartographic mapping systems may be categorized into 3D visualization systems handling terrain height-field processing, 2D GIS extension modules, or 3D geometric feature generation system using orthophoto image: actually, these are eventually considered as several parts of "real 3D GIS". As well as these things, other components, especially web-based 3D GIS, are being implemented in this study: Surface/feature integration, Java/VRML linkage, Mesh/Grid problem, LOD(Level of Detail)/Tiling, Public access security problem, 3-tier architecture extension, Surface handling strategy for VRML.

• Journal of Welding and Joining
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• v.25 no.3
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• pp.18-27
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• 2007

Laser welding process is widely used in the industrial field due to its numerous advantages: a small heat affected zone(HAZ), deep penetration, high welding speed, ease of automation, single-pass thick section capability, enhanced design flexibility, and small distortion after welding. The objective of this research works is to investigate the influence of the process parameters, such as the welding fur metals with CW Nd:YAG lasers. The bead-on-plate and Lap welding experiments are carried out for several combinations of the experimental conditions. In order to quantitatively examine the characteristics of the welding quality of the cross section, tensile stress behavior and the hardness of the welded part are investigated in comparison of the Nickel coated and Nickel uncoated S45C steel. As a result of experiment, nickel coated S45C Steel showed more even weld zone than Nickel uncoated counterpart upon lap welding. Also, it showed relatively small amount of internal defects and spatter, and Nickel coated S45C showed better weldability than Nickel uncoated S45C steel. The optimum welding process upon lap welding of Nickel coated S45C steel is when each laser power is 1900W; focal positions is -1mm; welding speed is $0.9{\sim}1.0m/min$. The heat input was $4.178{\sim}4.36{\times}103J/cm^2$.

• Journal of the Korea Society for Simulation
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• v.17 no.1
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• pp.17-22
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• 2008

Double-binary turbo code has been adopted as an error control code of various future communication systems including wireless metropolitan area networks(WMAN) due to its powerful error correction capability. One of the components affecting the performance of turbo code is internal interleaver. In 802.16 d/e system, an almost regular permutation(ARP) interleaver has been included as a part of specification, however it seems that the interleaver is not optimized in terms of decoding performance. In this paper, we propose three optimization methods for the interleaver based on spatial distance, spread and minimum distance between original and interleaved sequence. We find optimized interleaving parameters for each optimization method and evaluate the performances of the proposed methods by computer simulation under additive white Gaussian noise(AWGN) channel. Optimized parameters can provide up to 1.0 dB power gain over the conventional method and furthermore the obtainable gain does not require any additional hardware complexity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.4
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• pp.504-516
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• 1997

Recently scientists and engineers are developing a system to get waste heat of low-temperature level with advanced heat pump, which have not been used up to now. As the reason, it is necessary to examine capability of using waste heat which is raised up in the tunnel of subway out of widely distributed low-temperature waste heat in large cities. Therefore we surveyed thermal environment of the tunnel of subway in $S\check{o}my\check{o}n$, downtown of Pusan, from November 1995 to December 1996 and developed a program to predict the thermal environment of subway on the basis of experimental data and the geometries of tunnels. This paper has proved availability of waste heat of subway when the measured results obtained in subway in the winter time and the simulated results of thermal environment prediction program are compared, as well as has reported results of estimating reliability of the simulation program. As the result, the charateristics of thermal environment in the tunnel of subway in $S\check{o}my\check{o}n$ station in the winter time are to be followed; 1) temperature in the tunnel is about $10^{\circ}C$ higher than outside air temperature, 2) temperature change in the tunnel is less than that in the platform so that we may obtain stable heat source, 3) and when the measured results obtained in subway in the winter time and the simulated results of thermal environment prodiction program is compared, both results show similar tendency. Therefore, we confirm estimating reliability of the simulation program.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.4
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• pp.109-119
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• 2017

As advancement into global markets becomes increasingly important, there are increasing interests in high-tech companies' export. This study is an empirical investigation of the determinants of high-tech companies' export in the Daegu region seen from a resource-based perspective with focuses on organizational resources and innovative capabilities. The empirical analysis revealed that the export determinants hold truer for high-tech companies compared to companies overall, and that high-tech companies' key export determinants include organizational age as a organizational resource and international intellectual property rights (IPRs) as an innovative capability. In this sense, policies to promote high-tech companies' export should be designed to support high-tech companies that have a relatively longer history and international IPRs. The results also suggest that in the working level high-tech companies should establish their internal capabilities from a resource-based perspective, for example history and experience in their fields and international IPRs, rather than trying to target global markets from the beginning as born-global companies do.

• Smart Structures and Systems
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• v.15 no.3
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• pp.665-682
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• 2015

Structural identification or St-Id is 'the parametric correlation of structural response characteristics predicted by a mathematical model with analogous characteristics derived from experimental measurements'. This paper describes a St-Id exercise on Humber Bridge that adopted a novel two-stage approach to first calibrate and then validate a mathematical model. This model was then used to predict effects of wind and temperature loads on global static deformation that would be practically impossible to observe. The first stage of the process was an ambient vibration survey in 2008 that used operational modal analysis to estimate a set of modes classified as vertical, torsional or lateral. In the more recent second stage a finite element model (FEM) was developed with an appropriate level of refinement to provide a corresponding set of modal properties. A series of manual adjustments to modal parameters such as cable tension and bearing stiffness resulted in a FEM that produced excellent correspondence for vertical and torsional modes, along with correspondence for the lower frequency lateral modes. In the third stage traffic, wind and temperature data along with deformation measurements from a sparse structural health monitoring system installed in 2011 were compared with equivalent predictions from the partially validated FEM. The match of static response between FEM and SHM data proved good enough for the FEM to be used to predict the un-measurable global deformed shape of the bridge due to vehicle and temperature effects but the FEM had limited capability to reproduce static effects of wind. In addition the FEM was used to show internal forces due to a heavy vehicle to to estimate the worst-case bearing movements under extreme combinations of wind, traffic and temperature loads. The paper shows that in this case, but with limitations, such a two-stage FEM calibration/validation process can be an effective tool for performance prognosis.