• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.310-315
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• 2013

This paper presents a two-port time-domain reflectometry(TDR) measurement technique for extracting the complex propagation constant of a cross-linked polyethylene(XLPE) cable. For the extraction, a short pulse transmitted through the cable is measured in the time domain and analyzed in the frequency domain. The propagation constant of a 22.9 kV XLPE cable with a conductor area of 325 $mm^2$ is extracted up to a frequency of approximately 2.14 GHz. The $S_{21}$ measured using a network analyzer and the two-port TDR technique are compared for verification. As a result compared with previous TDR method, the upper possible frequency limit for extracting the propagation constant increases and the measurement error decreases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3797-3803
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• 2009

Innovative capacities and performance are essential for the growth of the IT industry and the development of the Korean economy. Global R&D centers are important sources of innovation in the IT industry. In order to identify the structure of the innovation environment of global R&D centers in IT industry, we conducted a field survey of 50 global R&D centers and 50 global R&D policy experts in IT industry. According to the empirical results obtained using the Linear Structure Model, it is suggested that, first, with regard to a short-term IT global policy, the direction of the Korean government's policy should act as a trigger to connect the research domain and the market domain; second, the government policy should act as a facilitator to connect the development domain and the research domain in the mid-term period; and, finally, the government's R&D policy should serve as a disseminator to connect technological capability and the market space domain in the long-term perspective. For an effective way of internationalizing innovation, IT policy planners should regard global IT R&D centers as the important components of national innovation system and encourage the effective involvements by them in the process of IT industrial innovation.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.6
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• pp.591-605
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• 2010

Recirculation of airmass in coastal region occurs because of the change from land to sea breeze and was shown to produce a contrary result on air quality. This study examines the numerical simulation to analyze the effect of recirculation flow in Gwangyang Bay, Korea. For this purpose two case studies are performed by the WRF-FLEXPART-CMAQ modeling system, each for a different Meso-Synoptic Index. Additionally this research make a comparative study of large domain (Domain L) and small domain (Domain S). The horizontal wind fields are simulated from WRF. Changes in the land-sea breeze have an effect on the particle dispersion modeling. The numerical simulation of air quality is carried out to investigate the recirculation of ozone. Ozone is transported to eastward under strong synoptic condition (Case_strong) because of westerly synoptic flow and this pattern can confirm in all domain. However ozone swept off by the land breeze and then transported to northward along sea breeze under conditions of clear sky and weak winds (Case_weak). In this case re-advected ozone isn't simulate in Domain S. The study found that recirculation of airmass must be concerned when numerical simulation of air quality is performed in coastal region, especially on a sunny day.

• Journal of Navigation and Port Research
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• v.42 no.3
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• pp.201-206
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• 2018

The purpose of this study is to estimate a proper Domain Watch between anchored vessels in order to propose a method for the efficient management of VTS(Vessel Traffic Service) of the N-anchorage in Busan harbor, which is the largest port in Korea. For this purpose, we proposed the calculation method of Domain Watch and investigated the ship length(L), the distance between anchored vessels ($D_{ij}$), the domain radius(R), and the domain radius vs L(R/L) during the peak time of the vessels in the latest usage of anchorage. As a result of technical analysis for the surveyed data, the minimum R/L for securing the safety distance between anchored vessels was selected based on 2.85 corresponding to the 70th percentile of the total data. This result was applied to the N-anchorage of Busan and compared with the 'Guidelines of Port and Harbor Design(2014)', and we have confirmed that it is reasonable to set the Domain radius with the minimum 2.85L or more in VTS. This study considers the safety management of anchorage for VTS. This study could contribute to the safety of vessels using anchorage and the safety management plan of VTS when it is applied to other ports in operation such as it was in Busan.

• Journal of Magnetics
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• v.11 no.2
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• pp.74-76
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• 2006

Dynamic behaviors of transverse domain walls (TDWs) in rectangular shaped thin-film magnetic nanowires with different widths under applied magnetic fields less than the Walker field were studied by micromagnetic simulations. It was found that the velocity of stable TDWs in the viscous region increases from 147 to 419 m/s and their mass decreases from $6.24{\times}10^{-23}\;to\;2.70{\times}10^{-23}kg$ with increasing strength of the applied magnetic field ranging from 5 to 20 Oe for the nanowire with a dimension of 10 nm in thickness and $5{\mu}m$ in length, and 50 nm in width. With increasing the width of nanowires from 50 to 125 nm at a specific field strength of 5 Oe, the TDW's velocity also increases from 147 to 246 m/s and its mass decreases from $6.24{\times}10^{-23}\;to\;5.91{\times}10^{-23}kg$.

• Knowledge Management Research
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• v.14 no.5
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• pp.55-79
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• 2013

This study primarily focused on the opportunity realization process of a korean venture firm based on university. This research examined the relationship between entrepreneurial intent and organizational learning produced in a sustainable opportunity realization process with technology/market domain shifts. Therefore, this research explores the determinants of sustainable growth of a venture firm at the organizational level and suggests optimal solutions for promoting entrepreneurial intent and opportunity realization for many entrepreneurs. The results showed that CEO's entrepreneurial intent is a key driving factor that can positive impacts on opportunity recognition and organizational learning based on university's expertise. Furthermore, the orientation of a entrepreneur can affect venture's technology/market domain shift through the advanced technological knowledge of university. In conclusion, this research sheds light on the growth of a venture firm based on university suggesting more customized solutions for many entrepreneurs. Implications for the results and the future directions are discussed.

• Journal for History of Mathematics
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• v.21 no.3
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• pp.157-182
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• 2008

TIMSS 2003 is the third and most recently round of IEA's Trends in International Mathematics and Science Study. In this study, I considered the changes of the mathematics cognitive domain in TIMSS and got some facts for developing assessment framework. And I analyzed 7 countries' achievement in the view of our country Korea, i.e. Singapore, Hongkong, Chinese Taipei, Japan, Netherlands, and Unites States. With the reliable and valid achievement scales for cognitive domains given by ISC, students' achievement scales were analyzed according to country, percentile, and sex in each cognitive domain.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1292-1297
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• 2000

For dynamic system under the external irregular disturbance, a performance of the controller designed by using of the 'Heo-stochastic control methodology' is investigated by simulations and experiments. MIMO Flexible cantilever beam, sticked with piezoceramics used as a sensor and actuator, under the irregular disturbance at bottom is modelled in physical domain. Dynamic moment equation about the system is derived through both the Ito's stochastic differential equation and Fokker-Planck-Kolmogoroff equation and also system's characteristics in stochastic domain is analyzed. In this study, the controller suppresses the amplitude of the system's moment response to the external disturbance. MIMO PI controller('Heo-stochastic MIMO PI controller') is designed in the stochastic domain and the response characteristics are investigated in the time domain

• Korean Journal of Child Studies
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• v.34 no.2
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• pp.121-138
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• 2013

The purpose of this study was to investigate the relationship between self-perceptions and school children's depression according to their gender. The participants comprised 578 school age children in Daegu or Gyeongbok Province. The participants completed measures of self-perception(SPPC) and depression(CDI). The SPPC consisted of 6 domains, self-perception(scholastic competence, social acceptance, athletic competence, physical appearance, behavioral conduct and global self-worth). The collected data were analyzed by means of MANOVA, Repeated measures MANOVA, and Multiple Regression Analysis(using SPSS PC(19.0 version). The results were as follows. (1) Among the domain specific areas of self-perception, global self worth scored the highest amongst the other subscales(scholastic competence, social acceptance, athletic competence, behavioral conduct and global self-worth) in both boys and girls. (2) Level of depression in school children differed according to sex and domain specific self-perception which was social acceptance, physical appearance, behavioral conduct and global self worth. (3) Self-perception on depression was a more salient predictor in girls than boys. Among the domain specific area of self-perception, global self worth was the best predictor in both boys and girls.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.2
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• pp.63-69
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• 1999

The frequency-dependent characteristics of the finline have previously been analyzed using several frequency domain approaches. But the time domain TLM method presented in this paper is another independent approaches for obtaining frequency domain results for finline. The structure analysed with this algorithm is unilateral finline in WR-62 waveguide enclosures and the symmetrical condensed node based on the properties of Huygen's scattering model is used. From the TLM results, the frequency-dependent scattering parameters of a unilateral finline have been calculated by Fourier transform of the time domain data. The numerical results are in good agreements with other paper, thus demonstrating the validity and usefulness of the proposed method.