Solusi Numerik Persamaan Gelombang Dua Dimensi Dengan Metode Beda Hingga Skema Eksplisit CTCS

Persamaan gelombang dua dimensi merupakan persamaan diferensial parsial yang merupakan representasi dari gelombang permukaan yang dihasilkan oleh aliran air. Tujuan daripada penelitian ini adalah untuk menganalisis solusi numerik persamaan gelombng dua dimensi dengan menggunakan metode beda hingga skema eksplisit CTCS (Center Time Center Space). Ada beberapa langkah untuk menyelesaiakan persamaan ini, diantaranya diskritisasi pada persamaan gelombang dua, diskritisasi terhadap kondisi awal serta kondisi batasnya dimensi dengan metode beda hingga pusat terhadap waktu dan ruang. Langkah selanjutnya adalah menentukan syarat kestabilan dan syarat konsistensi untuki menunjukkan bahwa solusi numerik tersebut mendekati solusi analitik. Setelah diperoleh syarat kestabilan dan konsistensi dari skema yang digunakan maka simulasi dari skema yang digunakan dapat dilakukan. Hasil simulasi menunjukkan bahwa penggunaan metode beda hingga skema eksplisit CTCS pada persaman gelombang dua dimensi stabil dengan syarat tertentu. Dari syarat kekonvergenannya skema eksplisit CTCS pada persamaan gelombang dua dimensi diperoleh order errornya . Selanjutnya untuk penelitian dapat meneliti tentang solusi analitik persamaan gelombang dua dimensi dengan menggunakan kondisi batas Neumann

ODACH: A One-shot Distributed Algorithm for Cox model with Heterogeneous Multi-center Data

Objective: We developed and evaluated a privacy-preserving One-shot Distributed Algorithm for Cox model to analyze multi-center time-to-event data without sharing patient-level information across sites, while accounting for heterogeneity across sites by allowing site-specific baseline hazard functions and feature distributions. Materials and Methods: We constructed a surrogate likelihood function to approximate the Cox log partial likelihood function which is stratified by site, using patient-level data from a single site and aggregated information from other sites. The ODAC estimator was obtained by maximizing the surrogate likelihood function. We evaluated and compare the performance of ODACH with meta-analysis by extensive numerical studies. Results: The simulation study showed that ODACH provided estimates close to the pooled estimator, which is obtained by directly analyzing patient-level data from all sites via a stratified Cox model. The relative bias was <1% across all scenarios. As a comparison, the meta-analysis estimator, which was obtained by the inverse variance weighted average of the site-specific estimates, had substantial bias when the event rate is <5%, with the relative bias reaching 12% when the event rate is 1%. Conclusions: ODACH is a privacy-preserving and communication-efficient method for analyzing multi-center time-to-event data, which allows the baseline hazard functions as well as the distribution of covariate variables to vary across sites. It provides estimates that is close to the pooled estimator and substantially outperforms the meta-analysis estimator when the event is rare. It is thus extremely suitable for studying rare events with heterogeneous baseline hazards across sites in a distributed manner.

Implementasi Sistem E-Rapor guna mengetahui Perkembangan Anak berbasis Moodle Studi Kasus Paud Azizah

Paud Azizah merupakan salah satu sekolah yang menerapkan metode BCCT (Beyond Circle and Center Time) sebagai Kurikulum Standar, Paud Azizah menggunakan metode ini untuk pembelajaran sinergis dengan strategi pembelajaran saat bermain atau bermain sambil belajar. Kegiatan yang dilakukan anak-anak serta perkembangan di sekolah akan dituliskan oleh guru lewat buku penghubung yang nantinya akan diberikan oleh orang tua wali murid sebagai hasil laporan. Tetapi tidak semua orang tua dari masing-masing anak membaca catatan di buku penghubung, dikarenakan orang tua yang mempunyai kesibukannya masing-masing. Untuk mengatasi permasalahan tersebut, maka pada penelitian ini dibuatlah sistem e-rapor berbasis Moodle. Sistem ini memungkinkan guru untuk membuat laporan perkembangan anak dan rapor sebagai evaluasi kegiatan belajar mengajar selama 1 semester. Peran Moodle sebagai sistem laporan perkembangan anak di Paud Azizah untuk membantu akses berkomunikasi antara guru dan orang tua/wali murid dengan mudah tanpa ada halangan yang menyulitkan kedua belah pihak. Penulis melakukan penerapan untuk membangun sistem Moodle di Paud Azizah dengan melalui beberapa rangkaian tahapan penelitian. Dimulai dari mengidentifikasi masalah pada studi pendahuluan dan literatur, melakukan analisis sistem berupa data dan informasi, membuat pernacangan sistem berupa desain mockup, implementasi sistem, dan melakukan pengujian sistem yang menerapkan metode UAT dengan membuat kuisioner untuk guru maupun wali murid di Paud Azizah sebagai hasil dari proses implementasi sebagai hasil dari proses implementasi.

How do treatment times impact on functional outcome in stroke patients undergoing thrombectomy in Germany? Results from the German Stroke Registry

Background Functional outcome post-stroke depends on time to recanalization. Effect of in-hospital delay may differ in patients directly admitted to a comprehensive stroke center and patients transferred via a primary stroke center. We analyzed the current door-to-groin time in Germany and explored its effect on functional outcome in a real-world setting. Methods Data were collected in 25 stroke centers in the German Stroke Registry-Endovascular Treatment a prospective, multicenter, observational registry study including stroke patients with large vessel occlusion. Functional outcome was assessed at three months by modified Rankin Scale. Association of door-to-groin time with outcome was calculated using binary logistic regression models. Results Out of 4340 patients, 56% were treated primarily in a comprehensive stroke center and 44% in a primary stroke center and then transferred to a comprehensive stroke center (“drip-and-ship” concept). Median onset-to-arrival at comprehensive stroke center time and door-to-groin time were 103 and 79 min in comprehensive stroke center patients and 225 and 44 min in primary stroke center patients. The odds ratio for poor functional outcome per hour of onset-to-arrival-at comprehensive stroke center time was 1.03 (95%CI 1.01–1.05) in comprehensive stroke center patients and 1.06 (95%CI 1.03–1.09) in primary stroke center patients. The odds ratio for poor functional outcome per hour of door-to-groin time was 1.30 (95%CI 1.16–1.46) in comprehensive stroke center patients and 1.04 (95%CI 0.89–1.21) in primary stroke center patients. Longer door-to-groin time in comprehensive stroke center patients was associated with admission on weekends (odds ratio 1.61; 95%CI 1.37–1.97) and during night time (odds ratio 1.52; 95%CI 1.27–1.82) and use of intravenous thrombolysis (odds ratio 1.28; 95%CI 1.08–1.50). Conclusion Door-to-groin time was especially relevant for outcome of comprehensive stroke center patients, whereas door-to-groin time was much shorter in primary stroke center patients. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03356392 . Unique identifier NCT03356392

Spatial Memory in Hamsters (Mesocricetus auratus):Depleting/replenishing Environments and Pre-choiceBehaviors in the Radial Arm Maze

Rodents’ spatial memory is traditionally assessed in the radial arm-maze (RAM). An accurate response pattern in the RAM is described as the tendency to visit a new arm after each choice (i.e. win-shift strategy). When this response pattern is found, it is said that the animal remembers the places visited. In the present experiment, 12 hamsters were assessed in the RAM under two conditions: the depleting condition, in which feeders were not rebaited after each visit; and the replenishing condition, in which, feeders were rebaited. We registered the number of new arms visited (hits), the time spent in the central area of the maze, and the behaviors emitted in the central area before each arm choice. Results showed that, regardless of condition, animals were significantly more likely to visit new arms. However, more pre-choice behaviors and a longer center time were observed in the depleting condition than in the replenishing one. It is discussed that hamsters have a win-shift strategy for hoarding behavior even when they do not need to remember the places visited, though they exhibited more pre-choice behaviors when searching for food in the depleting condition.