Judul: Analisis Kebutuhan Uji Profisiensi Laboratorium Pengujian Pangan Terakreditasi di Indonesia
Abstrak: Laboratorium pengujian memerlukan evaluasi untuk menjamin keabsahan hasil pengujiannya salah satunya dengan mengikuti uji profisiensi. Jumlah Penyelenggara Uji Profisiensi (PUP) bidang pangan di Indonesia belum memenuhi rasio dengan laboratorium pengujian yang membutuhkan layanan jasa uji profisiensi. Penelitian ini bertujuan untuk mengidentifikasi tingkat pemahaman laboratorium terkait uji profisiensi, menganalisis kebutuhan penyelenggaraan uji profisiensi lingkup pangan di Indonesia, menguraikan faktor-faktor yang menjadi pertimbangan laboratorium pengujian dalam mengikuti uji profisiensi, menganalisis media informasi yang efektif untuk menyebarluaskan informasi uji profisiensi. Penelitian dilakukan dengan metode survei, diikuti oleh 83 laboratorium pengujian pangan terakreditasi yang sebagian besar (69,78%) berasal dari pulau Jawa. Pemahaman laboratorium terhadap uji profisiensi secara umum dikategorikan baik (81,93%). Laboratorium pengujian mengikuti uji profisiensi satu kali dalam setahun (61,45%) dengan alasan keikutsertaan yaitu terkait proses akreditasi (69,51%). Ruang lingkup uji yang banyak dibutuhkan adalah lingkup kimia (proksimat) dan mikrobiologi pangan (81,44%). Jumlah PUP yang masih sangat terbatas menjadi kendala utama laboratorium dalam mengikuti uji profisiensi (53,01%). Faktor utama yang mempengaruhi keikutsertaan laboratorium dalam uji profisiensi adalah faktor status akreditasi PUP dan harga. Media yang efektif dan dapat digunakan oleh para PUP sebagai sarana menyebarluaskan informasi penyelenggaraan uji profisiensi adalah melalui website, penawaran langsung dengan e-mail, dan whatsapp.
Keyword: food testing laboratories, proficiency test, proficiency test provider, survey

Judul: Sistem Uji Profisiensi Produk Agroindustri untuk Akreditasi Laboratorium Nasional
Abstrak: Proficiency testing was inter laboratory comparisons. The same sample could have different test results when tested in some different laboratories. To find out and improve the performance of laboratories, proficiency testing can be done. Different evaluation of test results from participant laboratories could make different interpretations of the proficiency testing, which means it can also affect the assessment of the participant laboratories. The aims of this research are 1) to design a system for proficiency testing by using several evaluation methods of test results 2) to identify the testing methods used by the participant laboratories and possible causes of outlier laboratories. The method used in this research are: method 1: one round data selection by Grubbs and the rest of the data is calculated by Robust Z-Score; method 2: data selection by Grubbs several times until no more data can be excluded and the rest data is calculated by Robust Z-score; method 3: direct calculation by Robust Z-Score; method 4: calculation by reference value. The data used are the results of proficiency testing of cocoa powder, chili sauce and vegetable oil; reference values come from German reference laboratory; interview result from the stakeholders and field observations for related testing. The results show the median from Indonesian laboratories are not too different from the reference value; distributions of data are large enough, proved by CV robust larger than CV Horwitz (except for cadmium and the amount of dissolved solid); method 2 is chosen as the best method based on the smallest CV Robust; method 2 is the most sensitive which is giving the bigger number of outlier laboratories than methods 1 and 3; the number of outlier laboratories with method 2 are less than method 4; testing laboratories using National Standard of Indonesia (SNI) obtained satisfactory results (40% -100%) by method 2, for most of the test parameters; possible causes of outlier laboratories results come from a variety factors, particularly the implementation of testing that does not comply with the testing method.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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