• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.674-682
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• 2003

Ship autonomous navigation is designated as what computerizes mental faculties possessed of navigation experts, which are building navigation plans, grasping the situation, forecasting the fluctuation, and coping with the situation. An autonomous navigation system, which consists of several subsystems such as navigation system, a collision avoidance system, several data fusion systems, and a motion control system, is based on an intelligent control architecture for the sake of integrating the systems. The motion control system, which is one of the most essential system in autonomous navigation system, controls its propulsion and steering gears to move the ship satisfying its hydrodynamic characteristics. This paper is the study on the ship movement control system and its implementation which are totally developed and run on virtual-world system. Receiving the high-level control values such as a waypoint presented from the collision avoidance system, the motion control system generates them to low-level control values for propulsion and steering devices. In the paper, we develop a ship motion controller using Oldenburger's theory based on mathematical fundamentals, and simulate it with various scenarios in order to verify its performance.

• Journal of Environmental Impact Assessment
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• v.10 no.3
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• pp.211-221
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• 2001

Recognizing interaction between the environment and humans, the EIA(environmental impact assessment) movement has sought to promote more environmentally sound and informed decisions for the sake of human welfare. Therefore, most EIA programs require the consideration of human health impacts. Yet relatively few EIA documents adequately address those impacts. This study was carried out to investigate the role of EIA for reuniting the environment and human health, for preventing and reducing significant health risks, and for improving human health impact assessment by means of risk assessment. Risk assessment consists of 4 components; hazard identification, dose-response assessment, exposure assessment and risk characterization. Since most people spent their times in indoor, indoor air quality modelling can be used in exposure assessment and risk assessment. In this study, indoor $NO_2$ concentration and personal $NO_2$ exposure were estimated by Box Model using mass balance equation and time weighted average, respectively. The estimated indoor $NO_2$ concentration and the personal $NO_2$ exposure were compared by those measured, respectively. Subsequntly, health effect was assessed with these results. Consequently, exposure assessment and risk assessment using indoor air quality model may be considered to be applicable to EIA.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.35-39
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• 2001

The purpose of this paper is improvement the piezoelectric of Polyvinylidene fluoride(PVDF) organic thin films is fabricated by vapor deposition method. The piezoelectric of PVDF organic thin films attributed to dipole orientation in crystalline region. Also, the piezoelectric characteristic reduced that dipole moments orientation in crystalline region interfered with impurity carriers. Therefore, PVDF organic thin films fabricated with high substrate temperature condition for crystallinity improvement. The crystallinity of PVDF organic thin films fabricated by this condition increase from 47 to 67.8%. The ion density of PVDF organic thin films fabricated by substrate temperature variation from $30^{\circ}C$ to $105^{\circ}C$ decreased from $1.62{\times}10^{16}cm^3$ to $6.75{\times}10^{11}cm^3$ when temperature and frequency were $100^{\circ}C$, 10Hz, respectively. The $d_{33}$ and piezo-voltage coefficient of PVDF organic thin films increased from 20pPC/N to 33pC/N and $162.9{\times}10^{-3}V{\cdot}m/N$ to $283.2{\times}10^{-3}V{\cdot}m/N$, respectively. For the sake of the applications of piezoelectric sensor, we analyzed the output voltage characteristic as a function of the distance between an oscillator of 28kHz and PVDF organic thin film transducer. From this, we found that the output voltage is inversely proportional to the distance. At this time, the period was about $35.798{\mu}s$ and equal the oscillator frequency.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.31-39
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• 2012

On rainy days, water films form on wet road surfaces and reduce the braking force of vehicles, which often ends up in accidents. For safe driving, the road information signage provides information on road and weather conditions warning drivers of wet road conditions. Still, current information on road conditions is neither localized nor detailed but universal. The present study used the images on CCTVs installed on roads to compare the images of road surfaces in an attempt to suggest a mechanism determining factors that hamper safe driving based on the images. In the image comparison, a normal road image taken on a sunny day is used as an original image, against which road conditions occurring on rainy days are categorized and determined on a case-by-case basis to provide drivers with early warning for the sake of safe driving.

• Korean Journal of Materials Research
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• v.30 no.1
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• pp.1-7
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• 2020

Doping or incorporation with exotic elements are two manners to regulate the optoelectronic properties of transparent conducting (TCO) cadmium oxide (CdO). Nevertheless, the method of doping host CdO by CdTe semiconductor is of high importance. The structural, optical, and electrical properties of CdTe-doped CdO films are studied for the sake of promoting their conducting parameters (CPs), including their conductivity, carrier concentration, and carrier mobility, along with transparency in the NIR spectral region; these are then compared with the influence of doping the host CdO by pure Te ions. X-ray fluorescence (XRF), X-ray diffraction (XRD), optical absorption spectroscopy, and electrical measurements are used to characterise the deposited films prepared by thermal evaporation. Numerous results are presented and discussed in this work; among these results, the optical properties are studied through a merging of concurrent BGN (redshift) and BGW (blue shift) effects as a consequence of doping processes. The impact of hydrogenation on the characterisations of the prepared films is investigated; it has no qualitative effect on the crystalline structure. However, it is found that TCO-CPs are improved by the process of CdTe doping followed by hydrogenation. The utmost TCO-CP improvements are found with host CdO film including ~ 1 %Te, in which the resistivity decreases by ~ 750 %, carrier concentration increases by 355 %, and mobility increases by ~ 90 % due to the increase of N_carr. The improvement of TCO-CPs by hydrogenation is attributed to the creation of O-vacancies because of H₂ molecule dissociation in the presence of Te ions. These results reflect the potential of using semiconductor CdTe -doped CdO thin films in TCO applications. Nevertheless, improvements of the host CdO CPs with CdTe dopant are of a lesser degree compared with the case of doping the host CdO with pure Te ions.

• Clean Technology
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• v.17 no.4
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• pp.329-335
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• 2011

$SF_6$ gas is well known as a global warming gas. Global warming potential of $SF_6$ gas is 22,000 times higher than that of $CO_2$. Recycling of $SF_6$ gas is an essential technology for the sake of the environment and the economy. The recovery processes of $SF_6$ gas studied in this work were liquefaction, distillation, and crystallization processes because these processes were thought to be easily carried to the fields for recycling waste $SF_6$ gas. The processes were simulated and optimized using Aspen plus. The optimization problems were formulated to minimize energy consumption with satisfying product specification and desired recovery. The performance of the processes was compared based on the optimization results. Effects of major process variables on the recovery performance were investigated and optimal operation guide for changing product specification and product recovery was provided.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.176-181
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• 1980

As a part of experiments aimed to reduce the acidic taste of a soured fruit wine, a selected yeast strain was studied on its morphological and physiological properties as well as its fermentative characteristics of apple wine. The results obtained were as follows. 1. The selected yeast strain was identified as a strain of Schizosaccharomyces pombe. 2. The tolerance of the strain to metabisulfite in apple juice was stronger than that of wine yeast. 3. The growth rate of the strain was more rapid than those of wine yeast and Sake yeast when cultured in apple juice at $25^{\circ}C$, but it was decreased below the levels of others when cultured at $15^{\circ}C$. 4. The levels of ethanol production and acid reduction by the strain were high when the apple wine brewed at $25^{\circ}C$, while these were dropped significantly at $15^{\circ}C$.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.27-32
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• 2004

This study intended to identify how our children are aware of dental health and motivate them to learn reasonable knowledge about dental health. Furthermore, it also aimed to induce them to change their awareness and behavioral style about dental health, so that they may keep good habits for dental health for their lifetime. Total 1,044 samples were collected from children who were all 12 years old and lived in Seongnam city. During six months (June to December 2002), they were asked to participate in questionnaire survey about consumer behavior, knowledge, attitude, activity and self-diagnosis for dental health. The results of questionnaire survey can be outlined as follows: (1) The results of investigating consumer behavior for dental health showed that 34.5% of total respondents ever visited dental clinics once or more within latest one year, 21.4% ever visited dental clinics for the sake of prevention, 70.6% were instructed in dental health program, 31.7% were treated with the fluorination, 36.9% were treated with dental sealant, and 17.1% were treated with scaling, respectively. (2) For 10 items asking reasonable knowledge about dental health, respondents answered to 5.06 items on average. (3) For 10 items asking reasonable attitude for dental health, respondents answered to 5.41 items on average. (4) For 10 items asking reasonable behavior, respondents answered to 4.53 items. (5) For 10 items asking reasonable self-diagnosis for dental health, respondents answered to 5.65 items.

• Journal of Science of Art and Design
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• v.2
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• pp.239-293
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• 2000

The paper aims to study how to describe the rigorous position on which semantic elements are laid, within the visual space. This purpose is, first of all, for the construction of visual syntactical semantics of the visual space. For this aim, the preliminary research begins with some definitions on : 1) visual space, visual design, visual syntactical semantic meaning, 2) position, sequence of position, 2-dim. sequence of position, and 3) 2-dim. numerical series of position, harmonious dynamic values. Here, The main issue is to define the position in general. To solve this problem, the researcher surveyed the positions on which the sets of pixemes are set up. The results are as follows ; 1. As far as the positions in visual space are concerned, they are the possible locations permitted in the visual patches. They are not the factual but the possible positions. 2.The position value that the sequential point has is not arithmetical but harmonious-dynamic, for it is not permitted for its own sake, but for the person, that is to say, for the viewer's visual perception. 3. The harmonious-dynamic value of positional sequence can be composed of the 2-dimensional successive numerical series which is, in turn, composed of the primordial 3 values x0, $\mu0$, y0. Here, the $\mu0$ is the harmonious mean value of x0 and y0. The x0 and y0 are, therefore, of the mutual dynamic relationship. 4. From this, the 2-dim general $\Delta-TABLE$ of the numerical series of position in visual design could be acquired through development of the primordial 3 values into the $X_i,\;Y_i$, orbit values.

• The Journal of Fisheries Business Administration
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• v.16 no.1
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• pp.31-54
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• 1985

The mutual credit of Fisheries Cooperatives is reciprocal financing bring overs and shorts to settlement themselves by filling each other's needs among feeble fishermen economically. The spread of mutual credit through Fisheries Cooperatives reduces private loan dependence and private loan interest rate at fishery village, and that fills up policy financing being restricted by working scale. And seeing movement side of Fisheries Cooperatives, it has done an under board to settle self-supporting foundation of primary fisheries cooperatives early. The mutual credit deposit shows about 53 times increase past an interval of a ten years. This increase rate is an epoch-making record being unparalleled in other banking facilities except Fisheries Cooperatives. Then being unparalleled increase rate, time and savings deposits increase has been contributed a great deal than demand deposits. Thinking important function factors as mutual credit growth, we can classify interior and exterior factors. The exterior factor is income of fishery household in some measure, interior factors are the high deposits interest rate and the enlargement of facilities organization. As these, they have been in a better factors, also have been a restriction factors. The restriction factors are conflict cancellation between mutual credit and them bring into existence a village vault, mutual savings and finance companies, private finance. For the sake of continuance growth rate in mutual credit as past, we should eliminate restricted factors in growth. On the other hand the better factors in growth should be act upon affirmation side continually. Consequently under circumstances not to an amicable settlement bring the fisheries fund demand as policy financing, we should do continuous and sound development of fisheries financing by means of putting in good order of fisheries cooperatives mutual credit. Surveying a problem from these viewpoints, when we study more deep and a full into a subject about growth project of mutual credit, we think to expect continuous growth in mutual credit of Fisheries Cooperatives.