• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.237-238
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• 2022

건설재해 감소를 위해서는 첫째, 관리자의 안전교육 이수 시간의 준수 및 안전교육 내용의 충실화가 요구된다. 둘째, 제도의 규제 이전에 자발적, 다각적인 안전점검의 시행이 요구된다. 셋째, 안전회의 및 교육과 점검이 이루어져야 할 것이며, 지정된 시기에 반드시 이루어져야 할 것이다. 넷째, 안전교육 및 회의의 활성화가 요구된다. 다섯째, 효율적인 건설 안전 관리를 위하여 건설 안전 기술 개발을 위한 연구개발, 투자의 확충 등이 요구된다.

• Journal of the Korean association of regional geographers
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• v.9 no.2
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• pp.119-134
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• 2003

This paper analyzes Wu Ha-Youngs Cheonilrok in order to reconstruct the regional characteristics of farming in the late 18th-century Korean countryside. The projected objective is approached through the examination of various indices drawn from the volume such as environment, distribution of arable lands, major crops, agricultural techniques, and productivity. The main finding of this research is that unlike todays homogenous picture of agriculture, quite significant differences of agrarian practices existed across the country in the past. The regional differentiation was attributable foremost to natural environment. To elaborate, landform, climate and soil influenced the distribution and use of land plots, the kinds of main crops produced, and the agricultural productivity. The region-specific agricultural techniques result from the cumulative processes of trial and error against the given environment. Other social and economic conditions which include population, skill of the peasants, size of landownership, and irrigation facilities sustained the regional differentiation of agriculture.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.406-412
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• 2009

Flight simulation model for helicopter simulator is one of the most important models which affect flight performance and handling quality. It is typical to develop the model based on the raw data and models from the helicopter designers/manufacturers. The approaches in this study were to develop the basic model based on the available resources regarding helicopter operation/maintenance and to tune and validate it based on the flight test results. The basic model was developed with maintenance manuals, flight manuals, analyses, measurements, papers and so on considering that KA-32T data could not be obtained from the manufacturer. The flight test for KA-32T was performed and the reference data for the simulation validation tests were acquired. The flight simulation model was validated to have the fidelity compatible with level C of FAA AC120-63 after comparison and tuning with flight test results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.159-168
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• 2012

In this paper, we designed the antipodal vivaldi antenna for IR-UWB systems application and evaluated IR-UWB antenna performance for the ultra wideband impulse signal transmission in the time- and frequency-domain. The designed antipodal vivaldi antenna was fabricated using FR-4 substrate which thickness 1.6 mm, dielectric constant ${\epsilon}_r=4.7$ and $tan{\delta}=0.002$. We measured the return loss, far filed radiation pattern at the anechoic chamber in the frequency-domain. We also performed the pulse fidelity analysis in the time-domain using nano-second impulse signal transmission and demonstrated the feasibility of ultra wideband signal stable transmission in the UWB band. The designed and fabricated antipodal vivaldi antenna could be emitting and receiving the IR-UWB signal while preserving low pulse distortion and good radiation pattern in time- and frequency-domain.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.4
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• pp.21-26
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• 1981

SnO2/n-Si and ITO/n-Si SIS solar cells have been fabricated ty mears of electron-beam deposition. The optimum oxidation and heat-treatment condition for SnO2/n-Si cells and ITO/n-Si cells are 50$0^{\circ}C$-5min., 30$0^{\circ}C$-10min., and 50$0^{\circ}C$-5min., 30$0^{\circ}C$-20min. respectively. The open-circuit Voltage(Voc), short-circuit current density(Jsc), fill factor(FF), and efficiency (η) under AMI(100mW/$\textrm{cm}^2$) illumination were 0.4V, 34mA/$\textrm{cm}^2$, 0.44, and 6.0%(active area efficiency, 6.9%) for SnO2/n-Si solar cells, and 0.44V, 36mA/$\textrm{cm}^2$, 0.53, and 8.45%(active area efficiency, 9.71%) for ITO/n-Si solar calls.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.553-563
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• 2010

This paper presents a tapered slot-antenna(TSA) for optimal impulse-signal transmission in ultra-wide band(UWB). The proposed TSA provides radiates in end-fire direction, which meets an impulse-radio UWB(IR-UWB) system demands(e.g., low loss, thus less error throughout the UWB band). In order to minimize the pulse distortion, we used an wideband impedance transformer and a microstrip slotline. The pulse fidelity characteristics was evaluated with finite-difference time-domain(FDTD) analysis technique and pulse fidelity correlation equation. Approximately 93.89 % pulse fidelity was obtained between the two antennas in 0.5 m range. Additionally, derived chirp Z-transform algorithm enables us to utilize the zoom-in option on the pulse signal in few nano-seconds below. Thus, it is possible to analyze the pulse signal distortion, delay or dispersion characteristics.

• Journal of Engineering Education Research
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• v.3 no.1
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• pp.12-20
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• 2000

In this paper, we are trying to explain an education method using the studio class where a lecturer can teach the theoretical approach for goals of theme, simulation for the theoretical results by using commercial CAD tools, and experiments for the simulation and design results. In order to apply the education skill using studio class to electrical engineering field efficiently, the theoretical approach, simulation procedure, and experiments should be coincided with each other. In this paper, the design procedure of low pass filter for undergraduate and graduate is chosen as an example of studio class In order to show the validity of the proposed education method. By considering the example, the efficiency of the method will be discussed.

• Communications of Mathematical Education
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• v.29 no.3
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• pp.313-330
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• 2015

The classification is an important activity that is directly related to concept formation. Thus it will need to be made meaningful learning to classification through learner-centered teaching. But we doubts weather teaching and learning to the classification are reflected in the constructivist philosophy of 'learner-centered' well or not. The purpose of this study was to analyze critically the content of elementary textbooks and guidebook for teachers relating to the classification of angles and triangles in terms of constructivism. As a result, there is a problem in the classification of angles that are not provided a reasonable chance to set criteria by agreement of the communities. There is a problem in the classification of triangles that has the characteristics of radical development in terms of diversity. In addition, response of students was predicted like anyone who already acquired knowledge. And it has the shortcomings that the opportunity to have a choice and a discussion to hierarchical and partition classification are not provided. The followings are proposed based on such features; faithful reflection of 'Learner-centered' principle, careful prediction of student response, teaching that focus on process than results.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.735-745
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• 1994

The incidence data (1991. 7. 1$\sim$1992. 6. 30) from the Implementation Study of Seoul Cancer Registry (ISSCR) were evaluated in terms of its completeness and validity. Two indicators for the completeness, Mortality/Incidence ratio (M/I ratio) and Age-specific Incidence Curve, showed fairy good registration throughout the age-sex specific strata, except the strata aged over 75 years old. The strata had very high M/I ratio (over 100%) and decreasing pattern of incidence, which suggested incomplete registration of cancer in this group. The active surveillance by a ISSCR staff improved the registration rate especially among elderlies. From the site specific M/I ratio, we found that liver cancer had oddly high M/I ratio. Since this high M/I ratio of liver cancer appears consistently in other reliable cancer registries, it is more like to be due to the high fatality of it rather than incomplete registration. The validity of the incidence data was assessed by three indicators; Histological Verification (HV%), Primary Site Unknown (PSU%), and Age Unknown (Age UNK%). The average HV% were 77% for men and 85% for women, which were slightly lower than those of other reliable cancer registries. This low HV% might be due to the considerable size of relative frequency of liver cancer in Korea, regarding the fact that the diagnosis of liver cancer is made mostly by non-biopsical radiologic methods (CT, Ultrasono, Angiography, MRI etc.). The level of PSU% and Age UNK% were in acceptable range, but not low enough, especially in terms of Age UNK%. Although ISSCR data had acceptable quality in general, it is needed to have more hospitals participate in the registry surveillance, to make registery data merged with death certificate data regulary, and educate the registration stans to be more competent and dedicated.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.100-109
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• 2011

This thesis is a content analysis on whether the proportion of structural element and theme association of television news imagery is different, depending on the historical background, and on what it means, which can be the index of scene-based and realistic report. Most researches of television news are horizontal studies of the same period, making light of vertical studies reflecting the change of age. Therefore, This study analyzed 729 items composed of 11,945 shots extracted from MBC Newsdesk from 1987, to 2007, the samples of which were extracted by systematic random sampling with five years' interval. This content analysis found out that there was high proportion of scene-based and realistic report such as 'sound-bite', 'event footage', 'direct matching' in the year 1987, 2007, and high proportion of 'corroboration shot', 'file footage', 'indirect reference', 'literal matching only' in the year 1997, which revealed the fact that reality-based report had not been faithfully accomplished in 1997.