• 분석과학
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• 제11권4호
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• pp.316-320
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• 1998

An image analysis was used for the interpretation of microstructures of ferrous metal artifacts. For the purposes, various microstructural features such as average grain size, phase area, shape factor, and composition of the inclusions, were parameterized for the information about manufacturing techniques such as casting, heating and tempering. The carbon content was determined through the evaluation of the amount of pearlite phase. As the amount of pearlite phase increased the shape factor also increased. Grain size was relatively smaller in trans-section than in cross-section. The manufacturing direction was trans-sectional because the orientation of inclusions was elongated lengthwise. All inclusions was of silicate groups and the manufacturing temperature was estimated up to $1450^{\circ}C$.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.475-478
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• 2006

In electrical impedance tomography (EIT) an array of electrodes is attached on the boundary of an object and small alternating currents are injected through these electrodes, and then the resulting voltages are measured. An estimation for the cross-sectional resistivity distribution in the object is obtained by using these current and voltage data in a nondestructive manner. In this paper, the electrical impedance imaging of two-phase flows undergoing rapid transient is considered with a special emphasis on the effect of the current pattern on the image reconstruction. The trigonometric current pattern, which is commonly used in the conventional static electrical impedance imaging, shows poor performance in case of the dynamic imaging considered in this work. Extensive numerical experiments are conducted with various kinds of current patterns and their effects on the image reconstruction performance are examined.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.189-190
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• 1998

In this paper, we show the realtime 3D reconstruction algorithm with the sliced CT images. The preprocessing is thresholding, labeling, contouring, and extracting dominant point. we reconstruct 3D image with dominant points using dynamic matching technique. The software implemented in Visualc++ 5.0 as a window-based application program.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (2)
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• pp.940-942
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• 2005

혈관내부의 초음파는 혈관 벽(vessel wail) 전체를 관찰할 수 있는 단면적 영상(cross-sectional image)으로부터 혈관 벽의 서로 다른 층을 평가할 수 있다. IVUS(Intravascular Ultrasound)영상은 잡음에 매우 민감하고 해상도가 낮기 때문에 혈관 벽의 서로 다른 층을 구분된다. IVUS영상이 내강, 혈관 벽, 외막을 둘러싸는 영역으로 구성되어있다고 가정하면 내부와 외부의 두 경계선으로 구분할 수 있다. 따라서 본 논문에서는 IVUS영상을 웨이블릿 변환하여 주파수 공간에서 관상동맥 벽의 두 경계선을 추출한다. 실험결과를 통하여 관상동맥 벽의 두 경계선이 잘 추출되는 것을 확인할 수 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.789-792
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• 2004

This study aims to detect only voids and estimate the cross-sectional size and thickness of voids using radar. A new method based on radar image processing is carried out with various void sizes and depths. The regression relationship between void size which has different depth and the amplitude characteristics of the radar return is considered in a new method of this research. For the purpose of examining; this regression relationship, experiments with change of void depth, surface area and thickness were carried out. Finally, the threshold value for image processing which aims to represent only voids to be fitted size (width) can be obtained. As the results, a proposed method in this study has a possibility of detecting only voids and estimating void size and thickness with good accuracy.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.472-472
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• 2010

The tomography has played a key role in tokamak plasma diagnostics for image reconstruction. The Phillips-Tikhonov (P-T) regularization method was attempted in this work to reconstruct cross-sectional phantom images of the plasma by minimizing the gradient between adjacent pixel data. Recent studies about the comparison of the several tomographic reconstruction methods showed that the P-T method produced more accurate results. We have studied existing Laplacian matrix used in Phillips-Tikhonov regularization method and developed modified Laplacian matrix (Modified L). The comparison of the reconstruction result by the modified L and existing L showed that modified L produced more accurate result. The difference was significantly pronounced when a portion of plasma was reconstructed. These results can be utilized in the Edge Plasma diagnostics; especially in divertor diagnostics on tokamak a large impact is expected. In addition, accurate reconstruction results from received data in only one direction were confirmed through phantom test by using P-T method with modified L. These results can be applied to the tangentially viewing pin-hole camera diagnostics on tokamak.

• The Korean Journal of Pain
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• 제36권4호
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• pp.465-472
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• 2023

Background: Percutaneous radiofrequency thermocoagulation (RFTC) has been widely utilized in the management of trigeminal neuralgia. Despite using image guidance, accurate needle positioning into the target area still remains a critical element for achieving a successful outcome. This study was performed to precisely clarify the anatomical information required to ensure that the electrode tip is placed on the sensory component of the mandibular nerve (MN) at the foramen ovale (FO) level. Methods: The study used 50 hemi-half heads from 26 South Korean adult cadavers. Results: The cross-sectioned anterior and posterior divisions of the MN at the FO level could be distinguished based on an irregular boundary and color difference. The anterior division was clearly brighter than the posterior one. The anterior division of the MN at the FO level was located at the whole anterior (38.0%), anteromedial (6.0%), anterior center (8.0%), and anterolateral (22.0%) parts. The posterior division was often located at the whole posterior or posterolateral parts of the MN at the FO level. The anterior divisions covered the whole MN except for the medial half of the posterolateral part in the overwrapped images of the cross-sectional areas of the MN at the FO level. The cross-sectional areas of the anterior divisions were similar in males and females, whereas those of the posterior divisions were significantly larger in males (P = 0.004). Conclusions: The obtained anatomical information is expected to help physicians reduce unwanted side effects after percutaneous RFTC within the FO for the MN.

• 대한의용생체공학회:의공학회지
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• 제18권4호
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• pp.365-373
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• 1997

본 논문에는 표면 형태만을 고려한 방법으로 다수의 단면 영상 데이터로부터, 관심있는 기관의 외부 표면을 패치(patch)에 의한 방법으로 재구성하여 삼차원적으로 표시하는 것을 목적으로 한다. 이를 위해 본 논문에서는 표면을 형성하기 위한 특징점을 추출하기 위하여 제거법에 의한 특징점 추출이라는 알고리즘을 제안하여 사용하였으며, 표면을 재구성하기 윟나 과정에서 두 단면의 영상의 특징점 사이의 최소 거리를 비용 함수로 사용하는 방법을 제안하였다. 제안한 알고리즘의 효용성을 확인하기 위하여 두부에 대한 이차원 CT 영상을 사용하여 실험을 실시하고 다른 방법과 비교하여 보았다.

• 대한간호학회지
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• 제46권1호
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• pp.118-127
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• 2016

Purpose: The study purposes were to construct and test structural equation modeling on the causal relationship of community residents' perceived quality of care, image, and role performance with satisfaction, intention to (re)visit and intention to recommend hospital. Methods: A cross-sectional survey was conducted with 3,900 community residents from 39 district public hospitals. The questionnaire was designed to collected information on personal characteristics and community awareness of public hospitals. Community awareness consisted of 6 factors and 18 items. The data were collected utilizing call-interview by a survey company. Research data were collected via questionnaires and analyzed using SPSS version 20.0 and AMOS version 20.0. Results: Model fit indices for the hypothetical model were suitable for the recommended level: ${\chi}^2=796.40$ (df=79, p<.001), GFI=.93, AGFI=.90, RMSR=.08, NFI=.94. Quality of care, image, and role performance explained 68.1% of variance in community awareness. Total effect of quality of care process factors on satisfaction (path coefficients=3.67), intention to (re)visit (path coefficients=2.67) and intention to recommend hospital (coefficients=2.45) were higher than other factors. Conclusion: Findings show that public hospitals have to make an effort to improve community image through the provision of quality care, and excellent role performance. Support for these activities is available from both Central and Local Governments.

• 유통과학연구
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• 제16권1호
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• pp.29-36
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• 2018

Purpose - The purpose of the research is to further explore the understanding of the nature of the brand distribution service (i.e., service brand) by undertaking a quantitative investigation. We focus on the role of customer's perception of service brand on the customer value creation process. Research design, data, and methodology - This study used single cross-sectional design and 137 airline passengers as respondents using a convenience random sampling. We distributed the online questionnaires by email address. The empirical setting for this research is airline service in Indonesia with a consideration that airline service has the useful context for this research as the service delivery process involve extensive customer interactions with the airline and its employees. We then analyzed the data using multiple regression (step-wise) method to fulfill the research objectives. Results - Using the step-wise regression method, the result shows that the influential factors to create customer value are cost and company image. The result suggests a company to improve its costs components and its company image in order to increase the customer value. Conclusions - The research shows that costs play a critical role, and completed with the company image to form the customer value variable. This shows that mostly customer formed their value based on costs they sacrificed. Mainly, this evaluation is monetary cost based, while Indonesian customers tend to have a high value for money demands.