• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.383-388
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• 1998

이동통신에서, 신호의 페이딩을 보상하기 위하여 pilot symbol assisted modulation(PSAM)에 대한 많은 연구가 진행 되어왔다. 본 논문에서는 최대비합성다이버시티를 사용하는 PSA-QAM에서 전력증폭기 비선형성의 효과를 분석하였다. 먼저, PSAM성능의 한계를 구하기 위하여, 페이딩에 대한 완벽한 정보가 주어진 상태에서 최대비합성다이버시티를 갖는 QAM의 이론적 성능을 분석하였다. 실제 PSAM에서, 페이딩에 대한 정보는 파일럿 심볼의 보간에 의하여 얻어진다. 오차의 평균전력을 최소화하는 보간필터를 사용하여 필터의 탭수, 파일럿 심볼프레임 주기, 도플러 주파수가 성능에 미치는 영향을 분석하였다. 비선형 전력증폭기 AB, B, C급의 AM/AM, AM/PM 특성을 성능분석에 고려하였다. 비선형 보상기술인 Cartesian Feedback Loop (CFB) 이용하여 AWGN 채널과 Rayleigh 페이딩 채널에서 비선형 전력증폭기 종류에 따른 성능변화를 나타내었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.611-613
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• 2017

This paper proposes a new method to reduce the overhead by pilots for single carrier frequency domain equalization (SC-FDE) transmission. In the conventional SC-FDE transmission structure, the overhead by transmitting pilot are heavy because the pilot are transmitted at every SC-FDE block. The proposed SC-FDE structure has fewer pilots and many SC-FCE blocks are transmitted between pilots. The channel estimation and equalization is performed at the pilot period and the channels between pilots are estimated through linear interpolation. This reduces the pilot overhead by reducing the pilot transmission compared with the conventional structure, and enables reliable channel estimation and equalization.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.9-16
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• 2008

Recently, there are a lot of multimedia products using image interpolation system. However, most interpolation systems in existence suffer visually to some extents from the effects of blurred edges and jagged artifacts in the image. In this paper, we propose a new adaptive linear interpolation system that uses the sub-pixel. The proposed system calculate the warped distance among the pixels of an image by optimizing length parameter. A new cost function is introduced to reflect frequency properties of the origin data in order to improve image quality. Experimental results show that our new algorithm significantly outperforms conventional interpolation methods in subjective quality, and in most cases, in terms of PSNR as well.

• Journal of the Korea Computer Graphics Society
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• v.1 no.2
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• pp.226-233
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• 1995

본 논문에서는 심장과 심장 상부의 대동맥 및 폐동맥에 대한 형태-기반 보간법을 이용한 3차원 가시화 방법을 제안하였다. CT, MR과 같은 의학 영상들은 x나 y축 방향보다 z축 방향으로 더 낮은 해상도를 갖기 때문에 3차원적 가시화를 위해서는 먼저 각 단층 영상들간의 보간이 수행되어야 한다. 그러나, 지금까지 대부분의 3차원 의학영상 가시화에서는 선형보간법이나 또는 그와 유사한 보간법들을 주로 사용했는데, 이런 보간법들은 분기나 휘어지는 구조를 갖는 기관에는 좋은 결과를 생성하지 못했었다. 따라서, 본 논문에서는 분기와 휘어짐이 있는 심장부위 구조를 3차원적으로 가시화하기 위하여 형태-기반 보간법을 이용하였다. 형태-기반 보간법을 이용한 가시화는 다른 보간법을 사용한 경우와 달리 분명하고 자연스러운 구조 표현을 할 수 있었고, 각 단층 영상간의 보간수를 증가시킴에 따라 더 좋은 결과를 생성하는 것으로 나타났다.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.2
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• pp.43-50
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• 2019

Purpose The principle of nuclear medicine test is divided into two main categories: competition(radioimmunoassay, RIA) and noncompetitive reaction(Immunoradiometric assay, IRMA). It is known that the curve fitting method, which is commonly used in inspection field, uses Spline interpolation in RIA method and Linear interpolation method in IRMA method. Among them, the insulin test using the IRMA test showed a significant difference, especially at low concentrations, despite the same algorithm of linear interpolation between fully automated radio immunoassay analyzers. In this study, we aim to obtain results from applying two different of algorithm using fully automated radio immunoassay analyzers including Gamma pro, Gamma 10, Cobra, and SR300. Materials and Methods A total of 30 test samples were selected for the test of TSH, ferritin, C-peptide, and insulin serum levels. Test was performed by IRMA method. We compared the difference in the results of applying the linear interpolation method and the spline interpolation method to Gamma Pro, Gamma 10, Cobra, and SR300 equipment. Results Two-way ANOVA was used for statistical analysis. The significance level was applied as P <0.05. The results of TSH, ferritin, C-peptide, and insulin tests were compared between the fully automated radio immunoassay analyzers. There was a significant difference between ferritin, C-peptide, and insulin serum levels(P<0.001). TSH didn't show any significant different between the devices(P=0.29). In the difference between linear and spline interpolation, there was no significant difference between insulin test(P=0.08), TSH test(P=0.81), and Ferritin test(P=0.06). However, C-peptide test showed a significant difference(P=0.03). Especially, the insulin test showed significant difference in lower ranges. As a result of comparing and analyzing the difference between the two interpolation methods, the devices in the low concentration group showed significant difference(P<0.001). Conclusion In case of new equipment in the laboratory it is necessary to recognize that there is a difference in the curve fitting method for each automated radio immunoassay analyzers in the low concentration area when the principle of inspection is IRMA method.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.23-28
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• 2011

Ultrasound images for the abdominal muscles are complicated enough to have difficulty in interpreting their results. For better interpretation, magnifying the original image is necessary but its magnified image could be deteriorated and suffer from information loss. Thus, in this paper, we propose a magnifying method that reduces the gap between the original image and the magnified one in quality using a fuzzy method with weights for its brightness and interpolation. The proposed method extracts information of pixels in magnified image that have most similar characteristics of the original one by applying fuzzy membership function. In the process, the difference in the brightness between pixels of the magnified image and the original one using bilinear interpolation method and the weight value using the interpolation from multiplied values of four pixels are supplied to the fuzzy membership function. In this experiment, the proposed method reduces the cloudy phenomenon appears commonly compared to the bilinear interpolation method among those qualitative issues of image interpretation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.8 no.2
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• pp.17-22
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• 1990

The Digital Terrain Model(DTM) data in the Geographic Information System(GIS) needs to be interpolated for various purposes. Three interpolation methods-Bilinear, Bicubic Spline, and Gregory-Newton interpolation-were used, compared, and analyzed in terms of the visual comparison and numerical analysis in the hilly terrain and relatively flat terrain.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.1-6
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• 2005

In this study, the method to improve positioning accuracy under the multi-DGPS coverage is suggested. the linearly interpolated PRC regenerating algorithm was applied to improve the DGPS positioning accuracy at user's position by using the various PRC information obtained from multi-DGPS reference stations. To test the performance of the suggested method, the RTK-GPS result was used as the reference and the quantitative analysis results of the performance of the developed navigation algorithm are presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.706-712
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• 2014

This paper describes a determining method of weighting factors for two-point interpolation filters. The interpolation filters is implemented by applying modifying functions to the linear interpolation. Here, there is a problem of determining weights when modifying functions being engaged. The previous method determined the weights by imposing c1-continuity on the interpolation kernels. However, this approach is unable to use the property of individual modifying functions. In this paper, on the basis of spectral analyses of the modifying functions and image signals, we provide a determination method by experimental results. Thus, many experiments are carried out to do so. The results indicate that different weights are required for different modifying functions and also the proposed method outperforms than the previous method.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.479-491
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• 2004

Location information of mobile objects is applied to vehicle tracking, digital battlefields, location based services, and telematics. Their location coordinates are periodically measured and stored in the application systems. The linear function is mainly used to estimate the location information that is not in the system at the query time point. However, a new method is needed to improve uncertainties of the location representation, because the location estimation by linear function induces the estimation error. This paper proposes an application method of the cubic spline interpolation in order to reduce deviation of the location estimation by linear function. First, we define location information of the mobile object moving on the two-dimensional space. Next, we apply the cubic spline interpolation to location estimation of the proposed data model and describe algorithm of the estimation operation. Finally, the precision of this estimation operation model is experimented. The experimentation comes out more accurate results than the method by linear function, although the proposed location estimation function uses the small amount of information. The proposed method has an advantage that drops the cost of data storage space and communication for the management of location information of the mobile objects.