64 research outputs found
Analisis Pemasaran Sosial dengan Metode SWOT pada Program Keluarga Berencana (KB) di Kantor Badan TASKIN PMPKB Kabupaten Tanah Datar: Indonesia
No full textABSTRACT
The purpose of this study is to analyze internal and external factors that influence the social marketing strategy of the Family Planning (KB) program at the Tanah Datar District TASKIN PMPKB Office and analyze what strategies are appropriate to be applied to the Tanah Datar TASKIN PMPKB Agency Office. In this study, the author uses the SWOT method to analyze internal and external factors and what strategies are appropriate to be applied to the TASKIN PMPKB Office of Tanah Datar Regency. Based on the SWOT analysis, the total score of the strength factor is more dominant or greater than the weakness factor at the Tanah Datar TASKIN PMPKB Office, which is 1.58 compared to 1.49.
While the external factor, the opportunity score is greater than the threat score at the Tanah Datar TASKIN PMPKB Office, which is 1.81 compared to 1.14, so it can be concluded that all existing weaknesses can be covered or overcome with strengths. exist, as well as threats that come from outside can be overcome with the opportunities that exist for the Tanah Datar District TASKIN PMPKB Office
Assessment of erosion rates and patterns from spatial variability of cesium-137
No full textSoil erosion predictions and mapping of erosion patterns are important for developing the corresponding management strategies to deal with soil erosion. This research was conducted; (i) to determine cesium sorption and desorption characteristics in soils, (ii) to develop a depth dependent model for predicting soil erosion from \sp{137}{\rm Cs} activity, and (iii) to define erosion patterns from measurements of the spatial distribution of \sp{137}{\rm Cs} within the field. Cesium sorption was more in soils with high clay or low sand content and neutral pH than soils with low clay or high sand content and having relatively acidic soil reaction. A significant relationship was also found between the sorption of Cs and soil organic-C content. Results indicate that Cs is strongly retained against exchange with Ca and Na in soils, but this degree of retention against exchange with K depends on the type of dominant clay mineral. A depth dependent model, polynomial method, was developed and used to predict soil erosion from the research field. The model accounts for initially higher rates of \sp{137}{\rm Cs} loss due to heterogeneity in mixing of \sp{137}{\rm Cs} in tillage layer for the first several years of cultivation. Furthermore, erosion rates estimated by the polynomial method do not depend on the depth of tillage, thus intermittent changes in cultivation practices and tillage depth do not influence erosion predictions. Annual estimated erosion rate using the polynomial method was 47.5% lower than the proportional method, but equivalent to the USLE. Mapping of soil erosion patterns from the spatial variability of \sp{137}{\rm Cs} indicated that greater than 97% of this field had eroded at a rate 2.5 times the soil loss tolerance for at least 27 years. Resulting erosion patterns can provide useful information that can contribute to our understanding of soil erosion processes. Subsequently this data can be used to help refine erosion control guidelines which influence the selection of a vast array of management practices by an agricultural producer including; tillage, fertilizer application, crop rotation, plant population, and structures
Editorial board member and prolific author status positively shorten publication time
No full textPublication speed is one of the important aspects of scholarly communication today since a good deal of research performance evaluation systems are based on published articles. This study aims to reveal the factors affecting the publication speed of journals. In this context, six library and information science (LIS) journals, ASLIB Journal of Information Management, Journal of Documentation, Journal of Informetrics, Journal of the Association for Information Science and Technology, Online Information Review, and Scientometrics are analysed in terms of their publication speed. Results show that being an editorial board member or prolific author for journals significantly shortens the duration of publication. Moreover, when there is at least one editorial board member or prolific author in the author group, the duration of the publication is shorter than the articles from the unknown authors. However, the fact that no significant difference is determined between single- and double-blind peer review and the duration of publication process gives an idea about the scientific levels of articles written by editorial board members or prolific authors. In this regard, our approach is to examine other factors affecting the publication speed by conducting multi-dimensional analysis in future studies
Full-Waveform Inversion for Breast Ultrasound
No full textBreast cancer is the most common type of cancer for women and in developed countries it forms one of their largest threats. Many studies have shown that early detection by screening is important for achieving a successful treatment and reducing the mortality rate. Nowadaysmammography is the gold standard for breast cancer screening. However, mammography has several drawbacks including the use of ionizing radiation, a painful procedure, and poor performance with dense breasts. Magnetic resonance imaging (MRI) could form an alternative as it has some powerful features. However, the high examination and equipment costs as well as the use of contrast agents limits its applicability. Another potential alternative for breast cancer screening is ultrasound. Ultrasound has the advantage over mammography orMRI that it is safe, cheap and patient-friendly. With ultrasound, a tumor can be detected since healthy breast tissues and cancerous tissues have different acoustic properties. All these features make ultrasound a promising candidate as a screening modality for breast cancer. Hand-held ultrasound scans are frequently used for breast imaging in hospitals. With these scanners reflectivity images are generated. These images typically show the boundaries between different tissues. Even when these exams are conducted by trained radiologists operator-dependency occurs. To eliminate this, automated full-breast ultrasound scanners have been developed where the transducer slides over the breast. However, as the imaging principle remains the same, only reflectivity images are generated. To avoid significant breast deformation as well as to scan the breast from as many sides as possible water-bath scanning systems have been developed. These systems have the additional advantage that both reflection and transmission measurements are obtained. This mixture of different measurement types make it feasible to obtain better images by employing advanced processing techniques. One promising imaging method is full-waveform inversion (FWI). FWI aims to match a modeled wavefield to a measured wavefield by adjusting the acoustic medium parameters. A minimization problem is constructed and solved to this aim. As a result, images showing quantitative information about the different tissues are obtained. This quantitative information aids to the characterization and identification of the different tissues. However, there are some challenges when applying FWI. One of the biggest challenges is its computational complexity. By the inclusion of wave phenomena such as diffraction, refraction, scattering and dispersion - needed to explain the measured data in great detail - the computational complexity of FWI has become significantly larger than conventional - mainly ray based - imaging methods. In this work, we investigate the applicability of contrast source inversion (CSI) as an FWI method for breast ultrasound. To this end, we first introduce our full-waveform forward modeling method which is based on solving an integral equation. With a synthetic example,we investigate howeach mediumparameter (compressibility, density, and attenuation) affects the scattered pressure field. The obtained results show that attenuation, in contrast to compressibility and density, has only little effect on the wavefield for frequencies below 1MHz. From that we conclude, that for these frequencies only attenuation can be neglected in our inversion. We also compare the results from our full-waveform modeling method with results obtained after commonly made approximations such as Born, ray-based and paraxial approximations. We observe from the presented numerical results that with each approximation important phenomena normally present in the full-wave data are absent. For this reason, we recommend to use a full-wave modeling method to compute synthetic measurement data.ImPhys/Medical Imagin
Multi-parameter inversion with the aid of particle velocity field reconstruction
No full textMulti-parameter inversion for medical ultrasound leads to an improved tissue classification. In general, simultaneous reconstruction of volume density of mass and compressibility would require knowledge of the particle velocity field along with the pressure field. However, in practice the particle velocity field is not measured. Here, the authors propose a method for multi-parameter inversion where the particle velocity field is reconstructed from the measured pressure field. To this end, the measured pressure field is described using outward propagating Hankel functions. For a synthetic setup, it is shown that the reconstructed particle velocity field matches the forward modelled particle velocity field. Next, the reconstructed particle velocity field is used together with the synthetically measured pressure field to reconstruct density and compressibility profiles with the aid of contrast source inversion. Finally, comparing the reconstructed speed of sound profiles obtained via single-parameter versus multi-parameter inversion shows that multi-parameter outperforms single-parameter inversion with respect to accuracy and stability. Accepted Author ManuscriptImPhys/Medical Imagin
Delft Breast Ultrasound: The development of a water-cup ultrasound breast scanning system
No full textBreast cancer is impacting over 1.5 million women each year. Early detection is essential in decreasing the mortality rate. Mammography is currently the golden standard for breast screening. However, this method is not ideal and water-bath ultrasound breast scanning is considered to be a promising screening modality. This type of scanning system is able to obtain ultrasound reflection and transmission data. In this study, a water-cup breast scanning setup is built. The setup consists of a plastic cup with four acoustic windows and four phased array ultrasound probes. The water-cup is used to execute a phantom study. The phantom study gives insight into the operability of the built water-cup. The differences between reflection and transmission data are observed and utilised. One imaging algorithm and two inversion algorithms are employed to reconstruct an image of the phantom. The images of the different algorithms are compared.Furthermore, a method is proposed that reduces the computation time of a reflection data based Born inversion algorithm. In the end, the water-cup is used to image an ex-vivo human breast. Finally, the limitations of the built water-cup are stated. In addition to manufacturing the water-cup, a pulse-echo-scan of an ex-vivo human breast is made. This pulse-echo-scan is compared with the cross-sectional photograph of the breast. Due to the pudding-like structure of the breast, it is challenging to make a cross-section at the same position as the pulse-echo-scan is made. The pulse-echo-scan is made at the Pathology Department of the Erasmus MC. The ex-vivo human breast study helps to understand what structures are present in the breast. This knowledge can be used to build a new measurement setup and optimize the imaging algorithms for finding tumours.Delft Breast Ultrasoun
Effect of Some Polymers on Soil-water Losses and Sediment Size depending on Initial Aggregate Size under Sequential Simulated Rainfall
No full textAbstractEarth is quickly changing in physical meaning. Especially as a result of climate change, increasing number of swelling-shrinking cycles that managed by wetting-drying and freezing-dissolving events in the soil, closely affects the aggregate stability. Main purpose of this study is to research the effects of polyvinyl alcohol (PVA) and polyacrylamide (PAM) which are applied to different size of aggregates of a Typic Xerorthent on the runoff and soil losses under the sequential simulated rainfalls in the laboratory. Other purposes of this study are to research efficiency duration of polymers as part of the fragmentation dynamics and to determine particle size distribution in transported material. At the aim of the project diverse aggregate sizes of the soil were put in soil pans. PVA and PAM were applied on these aggregates. Simulated rainstorms with 360mm h-1 intensity were applied by using “Eijkelkamp rainfall simulator” for a duration of 12minutes. After 48hours first rain application, sequential simulates rainfalls were applied on same pans. Particle size distribution was partially determined in sediments. In the end of the study, while minimum and maximum runoff quantities (RQ) were measured as 11.9mm (in > 6.4mm aggregates + PVA) and 40.6mm under first rainfall, respectively, these values were measured in the same application pans as 22.6mm and 49.1mm under sequential rainfall. In the first rain event, soil quantities transported by runoff (SQTR) were ranged from 89.1 to 3923.1g m-2 above application pans. In the second rain event, SQTRs were ranged from 91.8 to 4739.4g m-2 same pans. According to particle size analysis results polymers were found successful to keep particles together under first rain event.AcknowledgementsThis study was supported financially by The Scientific and Technological Research Council of Turkey (TUBITAK). We thank the said institute. Project Code: TOVAG/113-O-555
Breast Ultrasound: A comparison of different image reconstruction techniques
No full textBreast cancer is the most occurring cancer among women. Detecting it at an early stage enables to significantly reduce the mortality rate. Mammography is the golden standard technique used for screening but it has some disadvantages, among which the difficulty to scan women with dense breasts. Ultrasound is a promising technique enabling a cheap and fast diagnosis. More precisely, waveform inversion reconstructs the 3D speed of sound distribution within the breast, enabling an easier differentiation between healthy and non-healthy tissues.In this work, two inversion methods are investigated, namely Algebraic Reconstruction Technique (ART) and Born inversion. Born inversion is a non-linear waveform inversion method aiming at solving an integral equation. To increase its performance while keeping the computation time constant, the frequencies used for the reconstruction are chosen randomly over a given bandwidth for each source receiver combination, at the expense of an additional noise in the reconstruction. The sparsity of the reconstruction in the waveletdomain has been utilized to implement two new regularization methods aiming at reducing this noise. To test and validate the three algorithms (namely ART and Born Inversion with the two regularization methods), a phantom study has been performed with both synthetic and real data. The phantom, made out of agar, isplaced in a square water tank in the centre of a measurement setup designed during this study, allowing to scan the phantom from its four sides.The results of the methods are presented and discussed. ART does not perform well with real data as the assumption on which it relies is not satisfied at the frequencies used in this study. Born inversion is presented with transmission and reflection data, as well as a combination of the two. With synthetic data, both reflections and transmissions give very satisfying results with the help of the regularization. With real data the phantom is correctly imaged by the reflections but the transmissions do not perform well enough to give an accurate speed of sound map.The knowledge gathered in this work can help building a better measurement setup, with a phantom closer to the breast geometry and internal structure, with which the reconstruction techniques could be tested and further improved
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