Judul: Kesesuaian Periode Onset Kejadian Demam  Dengue (DD) dengan Onset Kejadian Hujan dan Surplus-Defisit Air di Provinsi Kalimantan Timur
Abstrak: Penularan Demam Dengue (DD) salah satunya dipengaruhi oleh unsur iklim, yaitu curah hujan. Kejadian penyakit DD seringkali bersamaan dengan terjadinya musim hujan. Untuk persiapan upaya preventif, informasi awal periode kejadian penyakit DD sangat diperlukan. Oleh karena itu, penelitian ini bertujuan mengidentifikasi periode onset kejadian DD berdasarkan onset kejadian hujan dan kondisi surplus-defisit air di Kalimantan Timur. Analisis periode onset dilakukan dengan menghitung anomali kumulatif data dengan rata-rata yang dihitung setiap tahun. Hasil analisis menunjukkan onset kejadian hujan sebagian besar terjadi pada dasarian I hingga II pada bulan Oktober, sedangkan onset kondisi surplus-defisit air terjadi pada periode yang sama hingga dua dasarian setelahnya, yaitu pada dasarian III Oktober hingga I November. Sementara itu, periode onset kejadian DD paling banyak terjadi pada bulan yang sama hingga dua bulan setelah onset kejadian hujan dan onset kondisi surplus-defisit air (Oktober-Desember), serta beberapa terjadi bukan setelah periode onset kejadian hujan maupun kondisi surplus-defisit air. Perbandingan kesesuaian antara periode onset kejadian DD dengan onset kejadian hujan dan kondisi surplus-defisit air tidak terlalu berbeda nyata walaupun onset kondisi surplus-defisit air terjadi pada satu hingga dua dasarian setelah onset kejadian hujan karena kesesuaiannya dengan periode onset DD dijelaskan dalam periode bulanan. Periode onset kejadian hujan tidak sepenuhnya dapat menjelaskan periode onset DD karena pola dan besarnya curah hujan yang terjadi pada periode sebelumnya dan saat terjadinya onset DD diduga juga berpengaruh, Dengue fever (DF) transmission is influenced by climate variables, including rainfall. DF incidences often occurs together with the onset of the rainy season. To prepare the preventive actions, early information on the period of DF incidences is needed. Therefore, this study was conducted to identify the onset period of DF events based on the onset of rainfall events and water surplus-deficit conditions in East Kalimantan. The onset period analysis was conducted by calculating the cumulative anomaly data with the average calculated annually. The analysis shows that the onset of rainfall events mostly occurred in the first to second decade of October, while the onset of water surplus-deficit conditions occurred in the same period until two decades later, that is in the third decade of October to the first of November. Meanwhile, the onset period of DF events mostly occurred in the same month to two months after the onset of rainfall events and the onset of water surplus-deficit conditions (October-December), and some occurred not after the onset period of rainfall events or water surplus-deficit conditions. The comparison of the suitability of the onset period of DF events with the onset of rainfall events and water surplus-deficit conditions was not significantly different even though the onset of water surplus-deficit conditions occurred one to two decades after the onset of rainfall events because the suitability of the DF onset period was described in monthly periods. The onset period of rainfall events was not able to fully explain the onset period of DF because of the pattern and amount of rainfall that occurred in the period before and during the onset of DF are also expected to influence.
Keyword: dengue fever, meteorological factor, onset period, rainfall, surplus-deficit

Judul: Appropriateness of the Onset Period of Dengue Fever with the Onset of Rainy Season and Determining the Level of Case Vulnerability in Central Java
Abstrak: Demam Dengue (DD) merupakan penyakit yang sering terjadi di Indonesia. Salah satu faktor iklim yang berpengaruh terhadap penyakit DD adalah curah hujan. Setiap daerah memiliki tingkat kerawanan kasus yang berbeda-beda, sehingga perlu penentuan tingkat kerawanan untuk menentukan prioritas penanggulangannya. Penelitian ini bertujuan (a) mengetahui kesesuaian periode onset kejadian DD dengan periode onset musim hujan (MH), serta (b) mengetahui tingkat kerawanan kasus DD di Provinsi Jawa Tengah. Periode onset MH ditentukan berdasarkan anomali kumulatif dan kriteria berjenjang BMKG. Periode onset kejadian DD juga ditentukan berdasarkan anomali kumulatif dimana nilai minimum diidentifikasi sebagai periode onset. Tingkat kerawanan ditentukan berdasarkan tingkat peluang dari nilai indeks kerawanan. Hasil menunjukkan bahwa penentuan periode onset MH berdasarkan metode kriteria berjenjang BMKG memberikan persentase kesesuaian lebih tinggi dengan onset kejadian DD yaitu sebesar 62% dibandingkan dengan metode anomali kumulatif dengan persentase sebesar 53%. Periode onset kejadian DD yang terjadi bersamaan dengan onset MH kebanyakan terjadi di bulan Desember. Tingkat kerawanan kasus DD berada pada kategori agak aman (2 kabupaten), agak rawan (1 kabupaten), rawan (3 kabupaten), sangat rawan (23 kabupaten/kota), hingga amat sangat rawan (6 kabupaten/kota)., Dengue Fever (DF) is a disease that often occurs in Indonesia. One of the climatic factors that affect DF disease is rainfall. Each region has a different level of case vulnerability, so it is necessary to determine the level of vulnerability to choose the priority of countermeasures. This research aims to (a) determine appropriateness of the onset period of dengue fever with the onset of rainy season (RS), and (b) determine the level of vulnerability for DF cases in Central Java Province. The onset period of RS is determined based on the cumulative anomalies and tiered criteria of BMKG. The onset period of DF events is also determined based on cumulative anomalies, which is the minimum value is identified as the onset period. The level of vulnerability is determined based on the probability level of vulnerability index. The results show that determining the onset period of RS based on tiered criteria of BMKG provides a higher percentage of appropriateness with the onset of DF events, namely 62% compared to the cumulative anomalies method with a percentage of 53%. The onset period of DF events which occurred simultaneously with the onset of RS mostly occurred in December. The level of vulnerability for DF cases is in the category of slightly safe (2 districts), slightly vulnerable (1 district), vulnerable (3 districts), very vulnerable (23 districts/cities), and extremely vulnerable (6 districts/cities).
Keyword: curah hujan, Faktor Meteorologi, demam dengue, kerawanan, periode onset

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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