Image reconstruction in fluorescence molecular tomography with sparsity-initialized maximum-likelihood expectation maximization

We present a reconstruction method involving maximum-likelihood expectation maximization (MLEM) to model Poisson noise as applied to fluorescence molecular tomography (FMT). MLEM is initialized with the output from a sparse reconstruction-based approach, which performs truncated singular value decomposition-based preconditioning followed by fast iterative shrinkage-thresholding algorithm (FISTA) to enforce sparsity. The motivation for this approach is that sparsity information could be accounted for within the initialization, while MLEM would accurately model Poisson noise in the FMT system. Simulation experiments show the proposed method significantly improves images qualitatively and quantitatively. The method results in over 20 times faster convergence compared to uniformly initialized MLEM and improves robustness to noise compared to pure sparse reconstruction. We also theoretically justify the ability of the proposed approach to reduce noise in the background region compared to pure sparse reconstruction. Overall, these results provide strong evidence to model Poisson noise in FMT reconstruction and for application of the proposed reconstruction framework to FMT imaging

SISTEM PAKAR DETEKSI STATUS GIZI DAN PSIKOLOGI ANAK MENGGUNAKAN METODE DEMPSTER SHAFER

Dalam bidang psikologi anak antara usia anak 5-10 tahun, penting untuk mengetahui gejala-gejala gangguan psikologi anak dalam tumbuh kembangnya dan mengurangi terjadi gangguan yang lebih  serius. Sistem pakar merupakan program komputer yang meniru proses pemikiran dan pengetahuan pakar dalam menyelesaikan suatu masalah tertentu.Metode  Dempster Shafer  merupakan metode perhitungan untuk menentukan besarnya tingkat kepercayaan dari bukti-bukti atau informasi yang ada, berdasarkan tingkat kepercayaan dari bukti-bukti atau informasi mengenai gangguan psikologi anak yang diduga.Berdasarkan hasil uji coba sistem pakar mampu mengidentifikasi dan pengambilan kesimpulan penyakit beserta nilai densitas , gejala-  gejala yang dirasakan pasien dan memberikan solusi penanganan.Kata Kunci : Status Gizi, Gangguan psikologi anak, Sistem Pakar, Dempster ShaferABSTRACTIn the field of child psychology for children between the ages of 5-10 years, it is important to know the symptoms of psychological disorders in the child's growth and reduce more serious disturbances. Expert systems are computer programs that mimic the thought processes and expert knowledge in solving a particular problem.Dempster Shafer method is a method of calculation to determine the confidence level of evidence or information, based on the confidence level of evidence or information regarding child suspected of psychological disorders.Based on the test results, expert system is able to identify the disease and conclude density values, the symptoms felt by the patient and provide management solutions.Keywords:Nutritional Status, child psychology Disorders, Expert Systems, Dempster ShaferMetho

Sistem Pakar Deteksi Status Gizi dan Psikologi Anak Menggunakan Metode Dempster Shafer

In the field of child psychology for children between the ages of 5-10 years, it is important to know the symptoms of psychological disorders in the child's growth and reduce more serious disturbances. Expert systems are computer programs that mimic the thought processes and expert knowledge in solving a particular problem.Dempster Shafer method is a method of calculation to determine the confidence level of evidence or information, based on the confidence level of evidence or information regarding child suspected of psychological disorders.Based on the test results, expert system is able to identify the disease and conclude density values, the symptoms felt by the patient and provide management solutions

Incorporating reflection boundary conditions in the Neumann series radiative transport equation: Application to photon propagation and reconstruction in diffuse optical imaging

We propose a formalism to incorporate boundary conditions in a Neumann-series-based radiative transport equation. The formalism accurately models the reflection of photons at the tissue-external medium interface using Fresnel’s equations. The formalism was used to develop a gradient descent-based image reconstruction technique. The proposed methods were implemented for 3D diffuse optical imaging. In computational studies, it was observed that the average root-mean-square error (RMSE) for the output images and the estimated absorption coefficients reduced by 38% and 84%, respectively, when the reflection boundary conditions were incorporated. These results demonstrate the importance of incorporating boundary conditions that model the reflection of photons at the tissue-external medium interface

Energy-Efficient Heterogeneous Cellular Networks with Spectrum Underlay and Overlay Access

In this paper, we provide joint subcarrier assignment and power allocation schemes for quality-of-service (QoS)-constrained energy-efficiency (EE) optimization in the downlink of an orthogonal frequency division multiple access (OFDMA)-based two-tier heterogeneous cellular network (HCN). Considering underlay transmission, where spectrum-efficiency (SE) is fully exploited, the EE solution involves tackling a complex mixed-combinatorial and non-convex optimization problem. With appropriate decomposition of the original problem and leveraging on the quasi-concavity of the EE function, we propose a dual-layer resource allocation approach and provide a complete solution using difference-of-two-concave-functions approximation, successive convex approximation, and gradient-search methods. On the other hand, the inherent inter-tier interference from spectrum underlay access may degrade EE particularly under dense small-cell deployment and large bandwidth utilization. We therefore develop a novel resource allocation approach based on the concepts of spectrum overlay access and resource efficiency (RE) (normalized EE-SE trade-off). Specifically, the optimization procedure is separated in this case such that the macro-cell optimal RE and corresponding bandwidth is first determined, then the EE of small-cells utilizing the remaining spectrum is maximized. Simulation results confirm the theoretical findings and demonstrate that the proposed resource allocation schemes can approach the optimal EE with each strategy being superior under certain system settings

Ciliary Body Seeding after Pars Plana Transvitreal Fine-Needle Aspiration Biopsy of Choroidal Melanoma

Purpose: To report ciliary body seeding 20 years after pars plana transvitreal fine needle aspiration biopsy (FNAB) of choroidal melanoma. Case Report: 67-year-old man with choroidal melanoma in left eye was previously managed with pars plana FNAB using a 25-gauge needle followed by plaque radiotherapy. Twenty years later, choroidal melanoma was regressed but there was a small flat focus of scleral pigment 3.0mm from the limbus at the FNAB site. Ultrasound biomicroscopy showed a contiguous ciliary body mass measuring 3.1mm in thickness. Tumor seeding in the anterior chamber angle was noted inferiorly. These findings suggested melanoma recurrence along the needle tract. Treatment was performed with Iodine-125 radioactive plaque covering entire anterior segment and ciliary body recurrence. The tumor regressed to 2.2mm over one year. Conclusion: Pars plana transvitreal FNAB of choroidal melanoma resulted in needle tract seeding in ciliary body and episcleral region 20 years later