• Journal of Korean Society of Coastal and Ocean Engineers
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• 제31권3호
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• pp.129-145
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• 2019

For the design of composite breakwater as representative one of the coastal and harbor structures, it has been widely discussed by the researchers about the relation between the behavior of excess-pore-water pressure inside the rubble mound and seabed caused by the wave load and its structural failure. Recently, the researchers have tried to verify its relation through the numerical simulation technique. The above researches through numerical simulation have been mostly applied by the linear and nonlinear analytic methods, but there have been no researches through the numerical simulation by the strongly nonlinear mutiphase flow analytical method considering wave-breaking phenomena by VOF method and turbulence model by LES method yet. In the preceding research of this study, olaFlow model based on the mutiphase flow analytical method was applied to the nonlinear interaction analysis of regular wave-composite breakwater-seabed. Also, the same numerical techniques as preceding research are utilized for the analysis of irregular wave-composite breakwater-seabed in this study. Through this paper, it is investigated about the horizontal wave pressures, the time variations of excess-pore-water pressure and their frequency spectra, mean flow velocities, mean vorticities, mean turbulent kinetic energies and etc. around the caisson, rubble mound of the composite breakwater and seabed according to the changes of significant wave height and period. From these results, it was found that maximum nondimensional excess-pore water pressure, mean turbulent kinetic energy and mean vorticity come to be large equally on the horizontal plane in front of rubble mound, circulation of inflow around still water level and outflow around seabed is formed in front of rubble caisson.

• Korean Institute of Interior Design Journal
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• 제20권6호
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• pp.331-339
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• 2011

The purpose of this study was to examine wandering behaviors of the elderly with dementia at elderly care facilities, thus finding out the current status of supportability and safety of wandering space for facility residents and looking into the convenience of management for the control and Support of the elderly with dementia in wandering space, from the aspect of managers. Study methods consisted of literature examination, on-site assessment and investigation, observation and questionnaire survey. And via a questionnaire survey of facility workers at study subject facilities, the current status and facility workers' perception of wandering space and their job-satisfaction were examined. Collected data of 133 respondents were used for analysis. Data were processed with the SPSS 18.0 program, and such analytic techniques as frequency, percentage, mean, multiple response analysis, chi-square test and correlation analysis were carried out. The problems of physical environment of wandering space for the elderly with dementia: First, it is urgent to establish wandering space. Second, thoughtlessly installed chairs in the corridor impeded wandering behaviors. Third, the grips installed in the corridor space were irregular, thus causing inconvenience for wandering behaviors. Thus making residents' use of it difficult. In order to improve these problems, it is necessary to newly or additionally establish wandering space and modify the location of chairs or establish alcoves, thus reducing impedimentary elements for wandering behaviors. Providing a proper wandering space is important for facility residents. And it is also important for facility workers to manage facility residents.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제34권6호
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• pp.623-628
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• 2010

This paper presents a wind-power-driven portable power source based on piezoelectric effect. Positive piezoelectric effect is one of efficient and widely used mechanisms for converting mechanical energy to electrical energy. However, for this mechanism, a periodic mechanical stress with a high frequency, as in the case of AC, has to be exerted; such stress cannot be exerted by the natural wind in the environment. The natural wind has a constant velocity with slow and irregular variations, as in the case of DC. In this paper, we propose a novel and simple mechanism to convert mechanical energy into electrical energy. The DC-like wind flow is passed through a propeller to convert it to an AC-like wind flow; the resultant AC-like periodic flow induces vibrations in a piezoelectric cantilever, thereby, generating electrical power. This system is expected to be one of practical solutions for wireless energy supply to ubiquitous sensor networks (USNs).

• Journal of the Korean earth science society
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• 제30권7호
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• pp.824-833
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• 2009

We analyzed a total of six months of geomagnetic data obtained at Cheonyang observatory, which is operated by Korean Meteorological Administration, to monitor earthquake precursors. Geomagnetic transfer functions (GTFs) and polarization values, which reflect the time-variations of the resistivity of subsurface, were estimated from 3-component geomagnetic data. The time-variant fluctuations were compared with the earthquake events occurred in the same period. Now that the daily GTFs show fairly irregular variations, we can not identify any correlation with the already occurred earthquakes and Kp index. On the other hand, we detect clear increases of the Ultra-Low-Frequency (ULF) band polarization values before the earthquakes, but the similar features are also observed even though the earthquake did not occur. This result may indicate that these time-variations are not just due to the earthquake precursor. For further understanding about these results, we need to investigate the relationship between the previous earthquake events and the geomagnetic data of other observatories.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제19권10호
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• pp.947-952
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• 2006

It has been confirmed that the inner defect of insulator and the perfect diagnosis for aging are closely related to safe electric power transmission system and that the detection of accident and diagnosis technique turn out to be very important issues. But perfect diagnosis is difficult because discharge pattern is irregular. Thus, we investigated discharge pattern using the new distribution statistical models with cross-inked polyethylene(XLPE) specimens. Voltage was applied to power frequency by step method, and calibration of discharge was set to 50 pC. After the voltage was applied, it measured the discharge occurring during 10s. We investigated discharge pattern using the K-means analysis and Weibull function. We also investigated variation of centroid and shape parameter due to variation of voltage. As a result of analyzing K-means, it was confirmed that cluster including many object numbers was formed by the presence of void. And result of Weibull distribution, it was confirmed that shape parameter of discharge varied from 1.28 to 1.62 in no void specimens, and that shape parameter of discharge number varied from 1.28 to 1.62. In the void, shape parameter of discharge varied from 5.66 to 6.43, and shape parameter of discharge number varied from 5.05 to 5.08.

• Journal of Nutrition and Health
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• 제38권2호
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• pp.125-143
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• 2005

The purposes of this study were to investigate the characteristics of lifestyle and dietary habits of the colorectal cancer patients in Daegu and Kyungpook areas and to collect the data useful for nutrition education for the prevention of colorectal cancer in this community. The case subjects of the study were 123 patients diagnosed recently as colorectal cancer at Kyungpook National University Hospital. The control subjects were 182 persons who did not have any gastrointestinal diseases, including the patients from the department of orthopedic surgery and healthy volunteers. The survey covering general characteristics, life style, dietary habits, eating behaviors, and food intake frequency was administered by individual interviews using questionnaires. The results of the study suggest that high BMI, daily life stress, pessimistic personality, lack of physical activities, and familial cancer history might be the possible risk factors for the incidence of colorectal cancer. Dietary factors suspected as risk factors for colorectal cancer in the present study included strong preferences to meats, salty and fatty taste foods, low intake of water, alcohol drinking, smoking, coffee intake and irregular eating habits. A high consumption of seaweeds, green-yellow vegetables, light-colored vegetables, and green tea was suggested as a preventive factor for colorectal cancer. It is recommended to conduct more extensive and systematic surveys in the near future to reconfirm the risk factors of colorectal cancer in consideration of the characteristic food culture in this community. The results of the present study may be applied to nutritional education for the prevention of colorectal cancer for the local residents. (Korean J Nutrition 38(2): 125～143, 2005)

• Bulletin of the Society of Naval Architects of Korea
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• 제27권2호
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• pp.31-39
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• 1990

Deck wetness phonomena has long been considered as one of the factors that degrade the performance of a ship in waves. In rough weather, the frequent shipping of water may give rise to the capsizing of the ship. Therefore an appropriate above water bow design is an improtant assert to a ship of which successful performance in rough weather is a prerequisite such as a warship. In this paper the experimental technique for estimation of deck wetness frequency is presented. The results of the model tests are compared with those of calculation using Ochi's formula. Finally the applicability of Ochi's formula is discussed.

• Journal of Broadcast Engineering
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• 제5권2호
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• pp.281-289
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• 2000

While acquiring images, the relative motion between the imaging device and the object scene seriously damages the image quality. This phenomenon is called motion blur. The peak-trace approach, which is our recent previous work, identifies important parameters to characterize the point spread function (PSF) of the blur, given only the blurred image itself. With the peak-trace approach the direction of the motion blur can be extracted regardless of the noise corruption and does not need much Processing time. In this paper stochastic peak-trace approaches are introduced. The erroneous data can be selected through the ML classification, and can be made small through weighting. Therefore the distortion of the direction in the low frequency region can be prevented. Using the linear prediction method, the irregular data are prohibited from being selected as the peak point. The detection of the second peak using the proposed moving average least mean (MALM) method is used in the Identification of the motion extent. The MALM method itself includes a noise removal process, so it is possible to extract the parameters even an environment of heavy noise. In the experiment, we could efficiently restore the degraded image using the information obtained by the proposed algorithm.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제23권4호
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• pp.173-179
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• 2013

Even though a rough diamond shape is irregular and rugged, it is easy to be processed to make gem, shaped facets (table, crown, pavilion and girdle) were precisely treated because they influence on the evaluation of diamond grading. Those specifications suitable for the standard round brilliant cut diamond polishing were investigated and in 95 % statistical confidence interval, standard deviation, mean and acceptable tolerance were examined. According to these variables (size, angle, depth, and thickness) distribution, the frequency analysis of ratings and proportions were compared with each other. The correlation between each variables and the evidence of influence represented in proportion were determined by the regression analysis applying LSM (Least Square Method). In this research, it was recognized that table sizes of the diamond jewels and pavilion depth (in %) influence the rating decision and in particular, the depth of pavilion acting as the main factor of proportions, also plays an important role in optical phenomena.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.178-183
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• 2008

The goal of this study is finding flow-map in conversation what is going on user and embodied conversational agent by analysing that conversation. Specifically, this study not only find elements of conversation, but also draw out patterns of conversation can be exist for dialogue ability between user and Embodied conversational agent. To do this, we collect data through in-depth one to one interview, and then we analysis collected data to try to find out element of user-agent conversation based on qualitative research refer to the theory of conversation analytics and type of conversation. As a result, six flow map is deducted Especially, the irregular conversation is hard to find in human-human conversation, and the frequency is the most in data. In addition, when elements of interruption came out, be hostile to partner or correct the press conversation. This study can have positive effect to embodied conversation agent developer, user and service offerer because this study find the type of conversation through analysis that between embodied conversational agent and user.