• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.13 no.1
• /
• pp.35-41
• /
• 2020

Fast Fourier transform (FFT) processors have been widely used in various application such as communications, image, and biomedical signal processing. Especially, high-performance and low-power FFT processing is indispensable in OFDM-based communication systems. This paper presents a novel radix-26 FFT algorithm with low computational complexity and high hardware efficiency. Applying a 7-dimensional index mapping, the twiddle factor is decomposed and then radix-26 FFT algorithm is derived. The proposed algorithm has a simple twiddle factor sequence and a small number of complex multiplications, which can reduce the memory size for storing the twiddle factor. When the coefficient of twiddle factor is small, complex constant multipliers can be used efficiently instead of complex multipliers. Complex constant multipliers can be designed more efficiently using canonic signed digit (CSD) and common subexpression elimination (CSE) algorithm. An efficient complex constant multiplier design method for the twiddle factor multiplication used in the proposed radix-26 algorithm is proposed applying CSD and CSE algorithm. To evaluate performance of the previous and the proposed methods, 256-point single-path delay feedback (SDF) FFT is designed and synthesized into FPGA. The proposed algorithm uses about 10% less hardware than the previous algorithm.

• Journal of radiological science and technology
• /
• v.35 no.2
• /
• pp.133-139
• /
• 2012

For the examination of nuclear medicine, myocardial scan is a good method to evaluate a hemodynamic importance of coronary heart disease. but, the automatized qualitative measurement is additionally necessary to improve the decoding efficiency. we suggests the creation of cardiac three-dimensional model and model of three-dimensional cardiac thickness as a new measurement. For the experiment, cardiac reduced cross section was obtained from SPECT. Next, the pre-process was performed and image segmentation was fulfilled by level set. for the modeling of left cardiac thickness, it was realized by applying difference equation of two-dimensional laplace equation. As the result of experiment, it was successful to measure internal wall and external wall and three-dimensional modeling was realized by coordinate. and, with laplace formula, it was successful to develop the thickness of cardiac wall. through the three-dimensional model, defects were observed easily and position of lesion was grasped rapidly by the revolution of model. The model which was developed as the support index of decoding will provide decoding information to doctor additionally and reduce the rate of false diagnosis as well as play a great role for diagnosing IHD early.

• The Korean Journal of Nuclear Medicine
• /
• v.24 no.1
• /
• pp.29-36
• /
• 1990

Most of the diagnostic methods currently used for the detection of neoplastic masses provide indirect evidence. To obtain greater specificity in the interpretation of neoplasias by in vivo methods, the immunological approach appears to be most promising. Two problems that interfered with progress in this field were the lack of tumor specific antigen and the lack of well-defined and reproducible antibodies. To improve the sensitivity and specificity of radioimmunoscintigraphy as a technique for tumor localization, the use of monoclonal antibodies, fragments of antibodies and single photon emission computerized tomography (SPECT) are reasonable. The obvious advantages of monoclonal antibodies are their homogeneity, their specificity for the immunizing antigen and the reaction with a single determinant-thus no large immunecomplexes with antigen are formed. Monoclonal antibody technique has recently provided an opportunity to reevaluate the role of nuclear medicine for the diagnosis of malignant diseases by using the immunological approach. Out first results by means of radioimmunoscintigraphy of CEA and CA 19-9 producing tumors using a cocktail of fragments F $(ab')_2$, of mocolonal antibodies to CA 19-9 and CEA labeled with $^{131}I$ (IMACIS-1) are reported. The aims of this investigation was to evaluate the role of immunoscintigraphy in patients with colorectal and other cancers for diagnosis of local recurrences and metastasis. This report contains results of the first 8 colorectal and pancreas cancer patients with the elevation of the level of serum CEA and/or CA 19-9. IMACIS-1 was injected intravenously during 30 minutes in 100 ml saline solution after skin test. Planar scintigrams were recorded 3, 5 and 7 days after the injection of the IMACIS-1. Anterior, lateral and posterior views of the liver as well as anterior and posterior views of the pelvis were obtained in each patients as an $^{131}I-antibody$ image. We were able to localize exactly the malignant process with the double-nuclide double-compound $^{99m}Tc\;^{131}I$ (Tc+l) scintigrams. In Tc & I double-nuclide scintigraphy, computer subtraction display provided more clear localization of the tumor. We compared the results of radioimmunoscintigraphy with CT, ultrasonograms, conventional scintigrams. The results were as follows: 1) The sensitivity and specificity of radioimmunoscintigraphy using the fragments $F(ab')_2$ of the cocktails of CEA and CA 19-9 monoclonal antibodies were 80% and 100% respectively. 2) Tumor detection rate was not proportionated to the level of serum tumor markets. 3) Second tracer technique was essential for tumor localization as an anatomic landmark using double-nuclide scintigraphy. 4) A slow infusion of the antibodies was necessary to prevent the formation of large immune complexes. 5) Tumor/non-tumor radioactivity was most elevated at 7 days delayed imaging. 6) Using planar scintigraphic technique of $^{131}I$ labeled monoclonal antibodies are possible for imaging most of the tumors.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.2
• /
• pp.168-172
• /
• 2001

Objective : The authors have studied the clinical outcome of patients with diffuse axonal injuries(DAI) to evaluate the prognostic value of gradient-echo MR imaging findings. Materials and Methods : From March 1995 to March 1998, there were nineteen patients with DAI whose initial Glasgow coma scales were eight or less. Authors divided them into two groups according to Glasgow outcome scales ; those patients with GOS 3 or less(group A ; 9) and those with 4 or more(group B ; 10). We subdivided the lesions as superficial and deep lesion, and analyzed the numbers, anatomical loci of the lesions on the gradient echo images of each group. Results : Mean numbers of the lesions were 15 per case in group A(135/9) and 10 in group B(100/10). The common loci involved in DAI were cerebral cortex, brain stem, and corpus callosum. Cortical lesions were 31.1% in group A(42/135) and 47% in group B(47/100). Brain stem lesions were 25.9%(35/135) and 15%(15/100) each. Callosal lesions were 31.1%(26/135) and 13%(13/100) each. The frequency of callosal and brain stem lesions was significantly different between two groups(p<0.05). We divided callosal lesions as genu, body, and splenium and body lesions as anterior, middle, posterior, but no significant topographical difference of lesions was observed between two groups. Deep lesions were observed more frequently in group A(58.5%, 79/135) than group B(36%, 36/100). Conclusion : The poor outcome group showed more numbers of lesion and more frequent involvement of brain stem and corpus callosum than favorable outcome group. Gradient-echo MR imaging seems to have predictive value for clinical outcome in patients with DAI.

• Journal of the Korean Geotechnical Society
• /
• v.37 no.10
• /
• pp.13-25
• /
• 2021

The most widely used method for determining the blast effects of explosives is the Trauzl test. This test is used to measure the explosive power (strength) of a substance by determining volume increase, which is produced by the detonation of a tested explosive charge in the cavity of a lead block with defined quality and size. In this paper, Trauzl lead block test and High speed 3D-DIC (Digital Image Correlation) system were conducted to evaluate the stemming effect of the blast hole. The effects of stemming materials can be expressed as the expansion of the cavity in a standard lead block through explosion of the explosives. The blasting experiment was conducted with emulsion explosives. The stemming material in the blast hole of lead block, which was adopted in this study, were using sand and stone chips. Results of blasting experiment and numerical analysis showed that the expansion rates of lead block were most affected by stone chips followed by sand. Also, as result of dynamic strain measurement on the lead block surface of High speed 3D-DIC system, the displacement and surface strain on the block were the highest in the experiment case of stone chips stemming.

• Journal of IKEEE
• /
• v.25 no.3
• /
• pp.485-492
• /
• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.1
• /
• pp.47-54
• /
• 2021

Calculation of quantity at construction sites is a factor that has a great influence on construction costs, and it is important to calculate accurate values. In this study, topographic model was created by using drone photogrammetry and drone LiDAR to estimate earthwork volume. ortho image and DSM (Digital Surface Model) were constructed for the study area by drone photogrammetry, and DEM (Digital Elevation Model) of the target area was established using drone LiDAR. And through accuracy evaluation, accuracy of each method are 0.034m, 0.35m in horizontal direction, 0.054m, 0.25m in vertical direction. Through the research, the usability of drone photogrammetry and drone LiDAR for constructing geospatial information was presented. As a result of calculating the volume of the study site, the UAV photogrammetry showed a difference of 1528.1㎥ from the GNSS (Global Navigation Satellite System) survey performance, and the 3D Laser Scanner showed difference of 160.28㎥. The difference in the volume of earthwork is due to the difference in the topographic model, and the efficiency of volume calculation by drone LiDAR could be suggested. In the future, if additional research is conducted using GNSS surveying and drone LiDAR to establish topographic model in the forest area and evaluate its usability, the efficiency of terrain model construction using drone LiDAR can be suggested.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.47 no.4
• /
• pp.297-304
• /
• 2021

In this study, we prepared a pigmented skin model, KeraSkin-M^TM for the in vitro evaluation of whitening agents. For the purpose of complementing the existing mono-layer cell culture testing method, KeraSkin-M^TM was produced through the co-culture of human skin-derived keratinocytes and melanocytes. The efficacy of four well-known whitening agents (arbutin, ascorbic acid, kojic acid, niacinamide) was evaluated in KeraSkin-M^TM in order to assess its usefulness in assessing whitening efficacy. As a result, it was possible to observe additional details such as the distribution of melanin granules and melanin capping in each skin layer through KeraSkin-M^TM, which was previously difficult to assess in the traditional 2D cell culture system. In addition, quantification through image analysis of KeraSkin-M^TM allowed for a statistical analysis of the whitening effects. These results suggest that the KeraSkin-M^TM can be used as a new evaluation method of evaluating whitening efficacy, as well as complement the traditional total melanin content and tyrosinase inhibition assays.

• Journal of the Korean Society of Radiology
• /
• v.16 no.5
• /
• pp.537-543
• /
• 2022

The purpose of this simulation study was to evaluate the possibility of pancreas detection through effective atomic number information using dual-energy computed tomography(CT). The effective atomic number of 10 tissue-equivalent materials were estimated through stoichiometric calibration. For stoichiometric calibration, HU values at low-energy (80 kV) and high-energy (140 kV) for 10 tissue-equivalent materials were used. Based on this method, the effective atomic number image of the tissue-equivalent material was extracted through an iterative algorithm. According to the results, the attenuation ratio in accordance with the effective atomic number was estimated to have an R² value of 0.9999, and the effective atomic number of Pancreas, Water, Liver, Blood, Spongiosa, and Cortical bone was overall within 1% accuracy compared to the theoretical value. Conventional pancreatic cancer examination uses a contrast medium, so there is a possibility of potential side effects of the contrast medium. In order to solve this problem, it is thought that it will be possible to contribute to an accurate and safe examination by extracting the effective atomic number using dual-energy CT without contrast enhancement. Based on this study, future research will be conducted on the detection of pancreatic cancer using the HU value of pancreatic cancer based on clinical images.

• Journal of Society of Preventive Korean Medicine
• /
• v.27 no.1
• /
• pp.43-52
• /
• 2023

Objectives : The aim of this study was to evaluate the differences in the abdominal cavity between functional dyspepsia patients and healthy people using an algometer combined with an ultrasound device. Methods : A non-randomized, controlled, pilot trial was conducted. Thirty patients in the experimental group and fifteen participants in the control group were recruited. We collected demographical data, and measured abdominal circumference, height of the body cavity, subcutaneous fat thickness, visual analogue scale of dyspepsia symptoms in the experimental group, depth of algometer and pressure of algometer when pressure pain occurred, and the whole ultrasonic image from the beginning of pressurization to the time when pressure pain occurred. The measurements were carried out twice with the duration of 1 week. Generalized linear regression was conducted to adjust baseline characteristics. Results : A total of 45 participants (30 in experimental group, 15 in control group) were recruited and finished the trial. Females were recruited more in the experimental group than in the control group and it was statistically significant. The difference in thickness of abdominal cavity between a second before the pressure pain and at the time when pressure pain occurred was statistically significant on 1st visit, and other measurements were not statistically significant. From the results of the regression analysis, the difference between two groups was statistically significant in the differences in the thickness of stomach and up to abdominal aorta on 1st visit, and the thickness of stomach on 2nd visit, and other measurements were not statistically different. Conclusions : According to the results, there were not statistically significant differences in abdominal examination when pressure pain occurred between dyspepsia patients and healthy people. Further studies are warranted to assess the abdominal examination using devices including algometer and ultrasound devices, regarding the results of the present study.