• Journal of Information Display
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• 제3권3호
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• pp.1-11
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• 2002

Multi-view function is important to three-dimensional displays without dedicated glasses. It is the reason that the observers earnestly desire to change their positions freely. Multi-viewing is also principal to the reality of three-dimensional (3D) image displayed on the screen. The display of projection type has the advantage that the number of viewing points can be easily increased according to the number of projectors. The authors research on multi-view projection display with hologram screen. Powerful directionality of the diffracted beam from hologram screen is required unlike two-dimensional (2D) display. We developed a new method that all diffracted beams satisfied the same Bragg condition and became sufficiently bright to observe the 3D image under usual indoor light. The principle is based on the essential Bragg diffraction in the three-dimensional space. Owing to such three-dimensional Bragg diffraction we achieved an excellent hologram screen that could be multiple reconstructed in spite of single recording. This hologram screen is able to answer arbitrary numbers of viewing points within wide viewing zone. The distortion of 3D image becomes also sufficiently small with the method of dividing the cross angle between illumination and diffraction beam.

• Wind and Structures
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• 제25권3호
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• pp.261-282
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• 2017

The probabilistic information of directional extreme wind speeds is important for precisely estimating the design wind loads on structures. A new joint probability distribution model of directional extreme wind speeds is established based on observed wind-speed data using multivariate extreme value theory with the t-Copula function in the present study. At first, the theoretical deficiencies of the Gaussian-Copula and Gumbel-Copula models proposed by previous researchers for the joint probability distribution of directional extreme wind speeds are analysed. Then, the t-Copula model is adopted to solve this deficiency. Next, these three types of Copula models are discussed and evaluated with Spearman's rho, the parametric bootstrap test and the selection criteria based on the empirical Copula. Finally, the extreme wind speeds for a given return period are predicted by the t-Copula model with observed wind-speed records from several areas and the influence of dependence among directional extreme wind speeds on the predicted results is discussed.

• 대한인간공학회지
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• 제32권4호
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• pp.371-380
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• 2013

Objective: The aim of this study is to investigate the effects of design parameters of vibrotactile signals on semantic association with transmitted information conveying different meanings. Background: As information communication relying on human visual channel becomes excessive, the utility of vibrotactile signals is being interested as a substitute measure of delivering information. Properly designed hapticons may relieve burden of visual communication by rendering distinct and meaningfully compatible haptic sensations. Method: A typical Kansei engineering approach was adopted in this study. Ten most distinctive hapticons were selected among those having different frequencies and amplitudes. Associations between the hapticons and twenty four pairs of adjectives used to describe the state of automobile in control were gathered from thirty subjects using semantic differential scales. Results: The selected pairs of adjectives were summarized by factor analysis into two semantic dimensions named 'Awareness' and 'Directionality'. The experimental hapticons matched with the semantic dimensions were presented as a haptic emotion map. Conclusion: The results from this study support that frequencies and amplitudes of haptic signals play important roles in arousing different human perceptions regarding the two haptic emotional dimensions. Application: Properly designed hapticons with respect to the contents of transmitted information will increase human operator's situation awareness as well as system performance. The result from this study can be used to develop standardized hapticons for active haptic communication.

• 한국IT서비스학회지
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• 제14권3호
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• pp.163-182
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• 2015

The spread of mobile commerce due to popularization of smartphones not only broke down the boundary between online and offline, but also changed the consumer life, and hence brought change of commerce paradigm that creates new demand. The success of innovative information technology such as mobile shopping can be defined as an individual accepting the technology and continuously using it, but the studies on the usage behavior after the acceptance have been done in very restrictively, despite its importance. In this study, in order to empirically investigate the factors that influence the continuance in mobile shopping usage experience and its causal relationship, Social Cognitive Theory and Habit Theory were applied to IS Continuance Model, and the extended IS Continuance Model was suggested and proved. As a result, the usefulness, enjoyment, and self-efficacy perceived in usage experience significantly influence satisfaction, and usefulness, self-efficacy, and satisfaction influence habit. Also, usefulness, self-efficacy, satisfaction, and habit significantly influence continuance intention. This study provides a valuable asset in providing an opportunity to understand the usage behavior of mobile shopping service users after the acceptance, and furthermore proving directionality in improving customer loyalty.

• Journal of Microbiology and Biotechnology
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• 제26권8호
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• pp.1473-1480
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• 2016

This study focused on the variations in the non-coding sequences between ctxB and rstR of various CTX phages. The non-coding sequences of CTX-1 and CTX-cla are phage type-specific. The length of the non-coding region of CTX-1 and CTX-cla is 601 and 730 nucleotides, respectively. The non-coding sequence of CTX phage could be divided into three regions. There is a phage type-specific Variable region between two homologous Common regions (Common regions 1 and 2). The non-coding sequence of RS1 element is similar to CTX-1 except that Common region 1 is replaced by a short RS1-specific sequence. The non-coding sequences of CTX-2 and CTX-cla are homologous, indicating the non-coding sequence of CTX-2 is derived from CTX-cla. The non-coding region of CTX-O139 is similar to CTX-cla and CTX-2; however, it contains an extra phage type-specific sequence between Common region 2 and rstR. The variations in the non-coding sequences of CTX phages might be associated with the difference in the replication efficiency and the directionality in the integration into the V. cholerae chromosome.

• 한국정보처리학회논문지
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• 제3권3호
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• pp.683-695
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• 1996

본 논문에서는 화상내 객체의 윤곽정보를 얻고 객체내의 선분을 추출하여 이를 인덱싱하고 매칭하는 내용기반 화상정보 검색시스템을 구현하였다. 이를위해 선분추출 방법으로서 기존의 SLHT(Straight Line Hough Transform)의 단점을 개선시켜 FSLHT(Flexible SLHT) 를 제안하고 그 유효성을 입증하였으며, 선분에 의한 화상간의 유사도를 얻기 위해 (DP(Dynamic Programming) 알고리즘을 적용하였다. 윤곽특징을 고려할 때 화상의 윤곽이 잡음에 민감하게 반응하는 문제를 보완하기 위하여 일정간격으로 샘플링한 영역의 대 표값을 윤곽 특징으로 취하였으며, Hough 변환에 의한 선분 추출시 시각적인지에 기반한 방향성을 산출하여 변환함으로써 연속성상실 문제와 시간문제를 보완하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.272-272
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• 2013

The attractive features of photosynthetic reaction center proteins for energy application make them useful in solar energy conversion to hydrogen fuel or electrical energy. Almost unity charge separation quantum yield and its rapid speed of ~1ns, absorbance region in visible light (480~740 nm) and high proportion of photosynthetically active solar energy of 48.5% allowed photosystem1 to exploited as a bio-material for photo-energy devices. Directionality of photosystem1 in electron transfer can solve main problem in two-step water splitting process where back reaction deteriorates the overall efficiency. In the study, photosystem1 was extracted from spinach and the photo-induced excited electron in the reaction center was utilized in various field of light energy application. First, hydrogen evolving system realized by photodeposition of platinum at the end of the electron transfer chain, with combining specific semiconductor to oxidize water in the first step of Z-scheme. The evaluation by gas-chromatography demonstrated hydrogen evolution through the system. For the further application of photoelectrical material on electrode, photosystem1 have been controlled by copper ion, which is expected to assemble photosystem in specific orientation followed by maximized photoelectrical ability of film. The research proposed concrete methods for combining natural protein and artificial materials in one system and suggested possibility of designing interface between biological and inorganic materials.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.1083-1088
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• 2004

This paper deals with the vibration and stability of a circular cylindrical shaft, modeled as a tapered thin-walled composite beam and spinning with constant angular speed about its longitudinal axis, and subjected to an axial compressive force. Hamilton's principle and the assumed mode method are employed to derive the governing equations of motion. The resulting eigenvalue problem is analyzed, and the stability boundaries are presented for selected taper ratios and axial compressive force combinations. Taking into account the directionality property of fiber reinforced composite materials, it is shown that for a shaft featuring flapwise-chordwise-bending coupling, a dramatic enhancement of both the vibration and stability behavior can be reached. It is found that by the structural tailoring and tapering, bending natural frequencies, stiffness and stability region can be significantly increased over those of uniform shafts made of the same material. In addition, the particular case of a classical beam with internal damping effect is also included.

• 한국소음진동공학회논문집
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• 제14권7호
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• pp.639-647
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• 2004

This paper concerns the analytical modeling and dynamic analysis of advanced rotating blade structure implemented by a dual approach based on structural tailoring and viscoelastic material technology. Whereas structural tailoring uses the directionality properties of advanced composite materials, the passive material technology exploits the damping capabilities of viscoelastic material (VEM) embedded into the host structure. The main structure is modeled as a composite thin-walled beam Incorporating a number of nonclassical features such as transverse shear. anisotropy of constituent materials, and rotary inertia etc. The VEM layer damping treatment is modeled by using the Golla-Hughes-McTavish (GHM) method, which is employed to account for the frequency-dependent characteristics of the VEM. The displayed numerical results provide a comprehensive picture of the synergistic implications of both techniques, namely, the tailoring and damping technology on dynamic response of a thin-walled beam structure exposed to external time-dependent excitation.

• 한국해양공학회지
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• 제27권6호
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• pp.100-105
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• 2013

This paper presents a sea surface reconstruction method that uses measured radar images by applying filtering techniques and identifying wave characteristics of the surrounding the Ieodo ocean research station using WaveFinder (X-band wave measurement radar), which is installed in the station. In addition, the results obtained from real radar images are used to verify the reconstructed sea surface. WaveFinder is a marine system that was developed to measure wave information in real time. The WaveFinder installed in the station could acquire sequent images for the sea surface at constant time intervals to obtain real time information (Wave height, mean wave period, wave directionality, etc.) for the wave by getting a three-dimensional spectrum by applying an FFT algorithm to the acquired sequent images and wave dispersion relation. In particular, we found the wave height using the SNR (Signal to noise ratio) of the acquired images. The wave information measured by WaveFinder could be verified by comparing and analyzing the results measured using the wave measurement instrument (Sea level monitor) in the station. Additionally, the wave field around the station could be reconstructed through the three-dimensional spectrum and the inverse FFT filtering from the analyzed results for the measured radar images. We verified the applicability of the sea surface reconstruction method by comparing the measured and simulated sea surfaces.