• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.275-284
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• 2007

For precise interpretation of magnetotelluric (MT) data distorted by irregular surface terrain, topography effects are investigated by computing apparent resistivities, phases, tippers and induction vectors for a three-dimensional (3D) hill-and-valley model. To compute MT responses for the 3D surface topography model, we use a 3D MT modeling algorithm based on an edge finite-element method which is free from vector parasites. Distortions on the apparent resistivity and phase are mainly caused by distorted currents that flow along surface topography. The distribution of tipper amplitudes over both hill and valley are the same, while the tipper points toward the center of hill and the base of the valley. The real part of induction vector also points in the same direction as that of tipper, while the imaginary part in the opposite direction.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.11
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• pp.9-19
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• 1990

A theoretical analysis and measurement technique to determine the complex permittivity and permeability of cylindrical and ring type dielectric resonators is given. The resonant frequency, unloaded quality factor and physical dimensions of dielectric resonator placed between two parallel conducting plates are used to evaluate the complex permittivity and permeability. This process is repeated for other higher-order modes to expand the evaluation at higher resonant frequencies. The nature of each mode is identified by measuring the variations of field strength along the azimuthal and longitudinal direction. An error analysis taking into account various error sources reveals that $TE_{0np}$ or quasi-TE modes yield the least amount of measurement error, which is less than $0.5{\%}$for the real part, $4{\%}$for the imaginary part of complex permittivity.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.439-451
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• 2020

In order to deeply understand the significance of death aesthetics in contemporary art, this research first summarizes the development process of death aesthetics in art works with popular perspectives, and then classifies and discusses death aesthetics in modern art works. The results of this study are as follows: First, the aesthetic expressions of death are divided into two types: death reproducibility and death symbolism. Death reproducibility includes reproducibility of real objects and reproducibility of imaginary objects. The symbolism of death can be divided into external and internal manifestations. Secondly, in contemporary art, the reproducibility of death through the description of death scenes has increased the various problems and philosophical significance caused by death. Third, in contemporary art, the symbolism meaning of death is not just something directly related to death, it also shows the various psychological states brought about by death. Subsequent research will promote the artists' visual expression of the aesthetics of death in artworks, and the profound changes in meaning that result from it.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.263-267
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• 2020

In the Japanese colonial period of Korean history, appropriate conclusion often overwhelmed the historical imagination, and also pointed out that it shows a similar pattern in spite of the history detective novel genre that emerged with pointing out the limitations of modern history. Historical facts showing in , the legitimacy of independence based on nationalism, and modern civilization are well known in the historical and cultural contents of the Japanese colonial period. It is the reason why applied in historical and cultural contents, as the history as is for current desire of the public to the imaginary community(nation), and as the history which current social conflicts are reflected. History, historical facts and fiction are intermingled in the contents of history, and it is creating a new 'historical imagination'. As a matter of fact, there is only one fact of the past, but the historical imagination of historical and cultural contents is diverse as there is not one historical fact made by historians. History has not yet gone to the imagination for the future, but writing history through historical and cultural contents will create a 'history of possibilities'.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.153-168
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• 2003

It is very important to arrange the artificial teeth correctly in bucco-lingual (labio- lingual) relation in reconstrcting dentition. Although many anatomic landmarks and techniques have been reported over the years, they are based on westerns. So this study was performd to examine the horizontal relations of mandibular teeth in Korean dentulous adults. 200 volunteers(mean age 22.9) who had natural dentition were selected. The impressions were taken with irreversible hydrocolloid impression material and mandibular study models were fabricated using class I dental stone. Then they were measured with 3-dimensional measuring device specially designed for this study. The results were as follows ; It is better to consider the lingual cusps of the lower posterior teeth as a guide than the linguoaxial surfaces of the lower posterior teeth, arranging the lower posterior teeth buccally to the line which starts from the mesial aspect of the lower canine and continue backward to the lingual aspect of the retromolar pad. It is better to arrange the fossae of the lower posterior teeth buccally to the line which starts from the cusp tip of the lower canine and continue backward to the top of the retromolar pad. The positions of the lower posterior teeth in the denture-bearing area ; considering the fossa as a guide, the 2nd premolar was positioned in center. considering the buccal cusp as a guide, the 1st molar and the 2nd molar were positioned in center. the distance ratio(d/a) was incresed constantly from the lower canine to the 2nd molar d ; the distance between the buccal vestibule(the lowest point) and the buccal cusp tips of the lower posterior teeth. a ; the distance between the buccal vestibule(the lowest point) and the lingual vestibule(the lowest point). The lower canine was positioned lingually($0.11{\pm}0.13$) than the labial vestibule, and the central incisor and the lateral incisor were positioned almost in the imaginary perpendicular plane of the labial vestibule(the lowest point).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.889-891
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• 2017

Usually piston or rotary engines are installed at UAV's under 100 kg payload class. Those engine are less expensive and easy to get, but they require higher operating and maintenance costs due to shorter life and unique fuel usage. They are also too noisy to operate in urban area and have too strong vibration to carry sophisticated payloads. On the contrary, a gas turbine engine has drawbacks like higher specific fuel consumption and weight to power ratio, even it has many operating and maintenance benefits. This study aims to design a small turboshaft engine with a recuperator to overcome those demerits. A tilt rotor UAV(TR-60) developed by KARI was chosen as an imaginary target aircraft, and engine power and size were derived from it. This paper describes engine requirements, design process, and initial reference point cycle design.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.113-118
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• 2007

In this study, we select a site adopting real composite precast concrete method. Estimating real construction cost and imaginary cost appling reinforced concrete method in the site, we compare the costs. Through using high intensity concrete and prestressed concrete, amount of concrete is reduced more than 50% but there isn't big gap in material cost. In the main construction cost of composite precast concrete method, the material cost with production cost and transportation cost are in that, joints and topping concrete are account for 90%. But in case of reinforced concrete, labor cost spent at concrete steel bar and form is account for 30%. In the cost of attached, compared with composite precast concrete method, the reinforced concrete method taken in big portion by temporary work and scaffolding is twice as much as composite precast concrete method in construction cost. Therefore, economic efficiency is excellent reducing 11% total cost of composite precast concrete method from the reinforced concrete method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.2
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• pp.201-208
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• 2013

In this paper, the PTS scheme generate alternative orthogonal frequency frequency division multiplexing (OFDM) signal sequences by multiplying all the time domain samples with phase rotating vectors to find an OFDM signal having the minimum peak-to-average power ratio (PAPR). However, it needs an exhaustive search which causes large computational complexity. In order to solve this problem, we propose two efficient methods based on the crest factor. The first proposed scheme is to select time domain sample with large magnitude to calculate PAPR, and the next scheme is to calculate the absolute value of real and imaginary part of the sample at each subblock. The simulation results show that the proposed schemes achieve better PAPR reduction performance than existing PTS schemes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.1087-1094
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• 2014

An numerical technique of impedance boundary condition to improve an efficiency in the process of moment method with CFIE(Combined Field Integral Equation), which is widely used to analyze the scattering property of dielectric scatterers, and results of its cross-validations are presented in this study. Application of the impedance boundary allows to represent the equivalent surface currents of dielectric scatterer depicted by both kinds of electric/magnetic surface currents(Js, Ms) to the single surface current by Js or Ms only. Accuracy of this technique is validated by the existing CFIE and theoretical values such as Mie-series solution and small perturbation scattering model. The computational difference of less than 1 dB was verified within an imaginary part of dielectric constant more than 12, as well.

• Journal of the Korean Home Economics Association
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• v.40 no.10
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• pp.141-159
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• 2002

The purpose of this study is to find plan of practical using websites as welfare support system for present single-parent family practically. The subject websites were chosen by search in twice using Yahoo(http://www.yahoo.co.kr),Naver(http://www.naver.com).Empas(http://www.empas.com). The first search was accomplished by reference to these websites from the eighth of December to the twelfth of December in 2001. With the use of key words‘widowed mother & widower’,‘divorce’,‘single parent’,‘single-parent home’,‘single-parent family’. The second search was conducted on March 27, 2001. Finally 10 websites were selected. Chosen websites were analysed by structural element measure and structural technique measure of the contents. The following are summary of results and conclusion of this study. First, counsel program, self-help group, legal advice of the legal system and legal question area in the field of psychology·emotion·health problem of subject websites satisfied desire of single-parent family comparatively. Second, subject websites were classified into two types which are after the assessment of contents and structural technique of subject websites, a imaginary site was designed to solve the problem of single-parent family and to support single-parent family by means of prior research. Putting the result mentioned above together, As a step to solve the problem of single-parent family, to use practically website as a place single-parent family can be provided what the country and community cannot offer. It was accomplished by expanding self-help group extremely through the connection with ground to acquire strategy of dealing with single-parent family's desire and problem, volunteer supports and specialists.