• 대한가정학회지
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• 제40권4호
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• pp.179-200
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• 2002

The purposes of this study are as follows: (1) how are marital relationships classified by wives' perception of marital conflict and intimacy? (2) how do these types differ in terms of demographic variables (age, income, educational level, and employment status), individual psychological variables (self-esteem, differentiation) and interaction-related variables (affective self-disclosure, conflict resolution styles)?, and what are the relative discriminant powers of these variables in explaining marriage types? The data for this study were collected from 944 married women in Dajeon, who had one or more children, using the structured questionnaire. Classification using median and discriminant analysis were used with SPSS-PC for windows program. The major findings are as follows: The characteristics of each type are as follows: (1) The 'devitalized couples' consist of 18.2% of the whole sample. The levels of positive self-concept and positive interaction are the lowest. (2) The 'intimate couples' consist of 32.6% of the sample. They tend to be found most frequently in the population which is high in the educational level and income level and low in age. While the levels of positive self-concept and positive interaction are the highest, the levels of negative conflict resolution styles are the lowest. (3) The 'intimacy-persuaded couples' take 17.3% of the sample. The levels of positive self-concept and interaction are similar to the 'intimate couples'. (4) The 'conflict-habituated couples' take 31.9% of the sample. Whereas the levels of negative conflict resolution styles are the highest, the levels of positive self-concept and positive interaction are the lowest. The results of this study suggest several implications for the family-life education. It needs to apply different approaches to improve marital quality for each type of marriage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1194-1197
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• 2004

High temporal-resolution and accurate measurement of skin impedance locus provides useful data for the identification of the physiological/psychological changes and also the identification of acupuncture point. An impedance spectroscopy method using digitally constructed current waveform consisting of many frequency components (multiples of 1Hz) was reported3. The time resolution of the method depends on the lowest frequency used in the waveform construction, and therefore, the measurement would be faster if the lowest frequency is the higher. However, it was not clear that how many and how low frequencies must be used for the estimation of the skin impedance parameters from which the impedance locus can be drawn. This study shows the relationship between the estimation error of the impedance parameters and the frequency coverage of the spectroscopy. The results of this study are expected to serve as the reference of the frequency selection in the impedance spectroscopy.

• International journal of advanced smart convergence
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• 제8권3호
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• pp.95-101
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• 2019

Recently, there have been many issues related to text recognition using Tesseract. One of these issues is that the text recognition accuracy is significantly lower for smaller fonts. Tesseract extracts text by creating an outline with direction in the image. By searching the Tesseract database, template matching with characters with similar feature points is used to select the character with the lowest error. Because of the poor text extraction, the recognition accuracy is lowerd. In this paper, we compared text recognition accuracy after applying various super-resolution methods to smaller text images and experimented with how the recognition accuracy varies for various image size. In order to recognize small Korean text images, we have used super-resolution algorithms based on deep learning models such as SRCNN, ESRCNN, DSRCNN, and DCSCN. The dataset for training and testing consisted of Korean-based scanned images. The images was resized from 0.5 times to 0.8 times with 12pt font size. The experiment was performed on x0.5 resized images, and the experimental result showed that DCSCN super-resolution is the most efficient method to reduce precision error rate by 7.8%, and reduce the recall error rate by 8.4%. The experimental results have demonstrated that the accuracy of text recognition for smaller Korean fonts can be improved by adding super-resolution methods to the OCR preprocessing module.

• 방송공학회논문지
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• 제2권1호
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• pp.16-23
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• 1997

HDTV의 다음세대 TV로서 주목받고 있는 3D TV의 구현을 위한 주요 기술중 보는이의 시점에 해당하는 영상을 보여주는 다시점 입체영상표시가 중요한 연구대상으로 대두되고 있다. 본 논문에서는 다시점 입체영상표시를 구현하기 위한 기존방법들의 문제점으로 지적되는 많은 연산량 문제를 해결할 수 있는 새로운 알고리즘을 제안한다. 다시점 영상모음을 영상 공간축에서 을로 다운 샘플링(down sampling )하여 다해상도 영상 피라미드를 만들고, 이를 바탕으로 저해상도 EPI에서부터 대응점들을 탐색하고, 그에 해당하는 상위 해상도에서는 하위 해상도에서 탐색한 결과를 확인·교정해 가는 방법을 사용하므로써, 기존의 방법보다 고속처리가 가능하며, 잡음에도 강인한 기법을 제안한다.

• 한국해양공학회지
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• 제23권2호
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• pp.28-36
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• 2009

Many researches have been done to define the physical parameters for the wave generation and transformation over a coastal region. However, most of these have been limited to the application of particular conditions, as they are generally too empirical. To yield more reasonable wave estimation using a spectral wave model, it is important to understand how they work for the wave estimation. This study involved a comprehensive sensitivity test against the spectral resolution and the physical source/sink terms of the spectral wave model using SWAN and TOMAWAC, which have the same physical background with several different empirical/theoretical formulations. The tests were conducted for the East Anglian coast, UK, which is characterized by a complex bathymetry due to several shoals and offshore sandbanks. For the quantitative and qualitative evaluation of the models' performance with different input conditions, the wave elements and spectrums predicted at representative sites the East Anglia coast were compared/analyzed. The spectral resolution had no significant effect on the model results, but the lowest resolution on the frequency and direction induced underestimations of the wave height and period. The bottom friction and depth-induced breaking terms produced relatively high variations in the wave prediction, depending on which formulation was applied. The terms for the quadruplet and whitecapping had little effect on the wave estimation, whereas the triads tended to predict shorter and higher waves by energy transferring to higher frequencies.

• 대한원격탐사학회지
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• 제37권5_3호
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• pp.1461-1473
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• 2021

본 연구는 토지피복 자료의 공간 해상도가 미세먼지의 국지적 분포 및 확산 양상에 어떠한 영향을 미치는지 확인하는 데에 목적을 둔다. 이때 시공간적 지표상태 및 기상상태의 변화를 고려하는 CALPUFF 모델을 사용하여, 경기도 안양시의 평촌 신도시 지역에 대해, 미세먼지 모의를 진행하였다. 모델링의 입력 데이터로 20 m, 50 m, 100 m의 세 가지 해상도 토지피복도를 사용하여 비교하였다. 20 m 해상도의 토지피복 자료를 사용했을 경우 모의 영역의 풍속은 가장 크게 모의 되었으며 PM10 농도는 가장 낮게 모의 되었다. 본 연구를 통해 미세먼지의 국지적 분포 및 확산 양상에 토지피복 자료의 공간 해상도가 영향을 미칠 수 있으며 이는 CALPUFF 모의에 영향을 줄 수 있음을 확인하였다. 따라서 향후 CALPUFF를 사용하여 미세먼지를 모의할 때, 토지피복의 형태에 따른 공간 해상도에 대한 영향을 사전에 확인하고 모의를 진행하는 것이 더 정확한 결과를 확보할 수 있음을 제시해볼 수 있다.

• Journal of Astronomy and Space Sciences
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• 제40권1호
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• pp.35-44
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• 2023

Surveillance and reconnaissance intelligence in the space domain will become increasingly important in future battlefield environments. Moreover, to assimilate the military provocations and trends of hostile countries, imagery intelligence of the highest possible resolution is required. There are many methods for improving the resolution of optical satellites when observing the ground, such as designing satellite optical systems with a larger diameter and lowering the operating altitude. In this paper, we propose a method for improving ground observation resolution by using an optical system for a previously designed low orbit satellite and lowering the operating altitude of the satellite. When the altitude of a satellite is reduced in a circular orbit, a large amount of thrust fuel is required to maintain altitude because the satellite's altitude can decrease rapidly due to atmospheric drag. However, by using the critical inclination, which can fix the position of the perigee in an elliptical orbit to the observation area, the operating altitude of the satellite can be reduced using less fuel compared to a circular orbit. This method makes it possible to obtain a similar observational resolution of a medium-sized satellite with the same weight and volume as a small satellite. In addition, this method has the advantage of reducing development and launch costs to that of a small-sized satellite. As a result, we designed an elliptical orbit. The perigee of the orbit is 300 km, the apogee is 8,366.52 km, and the critical inclination is 116.56°. This orbit remains at its lowest altitude to the Korean peninsula constantly with much less orbit maintenance fuel compared to the 300 km circular orbit.

• The Journal of Advanced Prosthodontics
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• 제15권5호
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• pp.248-258
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• 2023

PURPOSE. This study aims to evaluate the effects of exposure energy on the lateral resolution and mechanical strength of dental zirconia manufactured using digital light processing (DLP). MATERIALS AND METHODS. A zirconia suspension and a custom top-down DLP printer were used for in-office manufacturing. The viscosity of the suspension and uniformity of the exposed light intensity were controlled. Based on the exposure energy dose delivered to each layer, the specimens were classified into three groups: low-energy (LE), medium-energy (ME), and high-energy (HE). For each energy group, a simplified molar cube was used to measure the widths of the outline (X_o and Y_o) and isthmus (X_i and Y_i), and a bar-shaped specimen of the sintered body was tested. A Kruskal-Wallis test for the lateral resolution and one-way analysis of variance for the mechanical strength were performed (α = .05). RESULTS. The zirconia green bodies of the ME group showed better lateral resolution than those of the LE and HE groups (both P < .001). Regarding the flexural strength of the sintered bodies, the ME group had the highest mean value, whereas the LE group had the lowest mean value (both P < .05). The ME group exhibited fewer agglomerates than the LE group, with no distinctive interlayer pores or surface defects. CONCLUSION. Based on these findings, the lateral resolution of the green body and flexural strength of the sintered body of dental zirconia could be affected by the exposure energy dose during DLP. The exposure energy should be optimized when fabricating DLP-based dental zirconia.

• 대한방사성의약품학회지
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• 제3권2호
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• pp.65-71
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• 2017

To assess the effects of filter and reconstruction of Cu-64 PET data on Siemens scanner, the various reconstruction algorithm with various filters were assessed in terms of spatial resolution, non-uniformity (NU), recovery coefficient (RC), and spillover ratio (SOR). Image reconstruction was performed using filtered backprojection (FBP), 2D ordered subset expectation maximization (OSEM), 3D reprojection algorithm (3DRP), and maximum a posteriori algorithms (MAP). For the FBP reconstruction, ramp, butterworth, hamming, hanning, or parzen filters were used. Attenuation or scatter correction were performed to assess the effect of attenuation and scatter correction. Regarding spatial resolution, highest achievable volumetric resolution was $3.08mm^3$ at the center of FOV when MAP (${\beta}=0.1$) reconstruction method was used. SOR was below 4% for FBP when ramp, Hamming, Hanning, or Shepp-logan filter were used. The lowest NU (highest uniform) after attenuation & scatter correction was 5.39% when FBP (parzen filter) was used. Regarding RC, 0.9 < RC < 1.1 was obtained when OSEM (iteration: 10) was used when attenuation and scatter correction were applied. In this study, image quality of Cu-64 on Siemens Inveon PET was investigated. This data will helpful for the quantification of Cu-64 PET data.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1361-1364
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• 1990

In order to tackle global environmental problems such as destruction of the ozone layer or climatic changes due to atmospheric temperature increase, the acquisition of plentiful and precise data is necessary. Therefore, a means of conducting long-lasting high-resolution measurements over broad areas is required. A feasibility study has been made on a high altitude (20km), super-pressured helium-filled PLTA (Powered Ligher-than-Air) vehicle as an ideal platform for environmental observation. It has a long service life and carries a larger payload than an artificial satellite. This PLTA platform uses an electric propulsion system to maintain position in space against wind currents. The thruster is driven by solar power acquired from solar cells. For night use, solar energy is stored in regenerative fuel cells. This study focuses on energy balance and structural analysis of the hull and platform. The platform is capable of conducting high resolution remote sensing as well as having the capability to serve as a telecommunications relay. The platform could replace a number of ground-based telecommunications relay facilities, guaranteeing sufficient radio frequency intensity to secure good quality telecommunication transmittal. The altitude at which the platform resides has the lowest wind flow in the lower stratosphere, and permits viewing from the ground within a 1,000km range. Because this altitude is much lower than that required of an artificial satellite, the measuring resolution is a couple of thousand times higher than with artificial satellites. The platform can also be used to chase typhoons and observe them from their sources in tropical regions.