Judul: Correlation of Milk Production and Quality in  Friesian Holstein Cattle with Rainfall in KPSBU Lembang West Java in 2022.
Abstrak: Produksi dan kualitas susu sapi Friesian Holstein di Indonesia masih rendah dibandingkan di daerah asalnya, Belanda. Produksi dan kualitas susu dipengaruhi banyak faktor lingkungan termasuk curah hujan. Kajian ini bertujuan mengetahui hubungan produksi dan kualitas susu dengan curah hujan di wilayah KPSBU Lembang Jawa Barat tahun 2022. Data produksi dan kualitas susu sepanjang tahun 2022 diperoleh dari Bagian Administrasi KPSBU Lembang, sedangkan data curah hujan bulanan sepanjang tahun 2022 diperoleh dari BMKG Jawa Barat. Data dianalisis dengan uji korelasi untuk menentukan koefisien korelasi (r) atau keeratan hubungan, dan uji regresi untuk menentukan koefisien determinan (r2) atau pengaruh dari curah hujan terhadap produksi dan kualitas susu. Hasil analisis menunjukkan curah hujan memiliki keeratan hubungan sangat lemah dengan produksi susu (r=0,044, r2=0,002), sedangkan kualitas susu memiliki keeratan hubungan dengan curah hujan dalam berbagai kategori; sangat lemah dengan total protein (r=0,010, r2=0,001), lemah dengan kadar lemak (r=0,118, r2=0,14) dan berat jenis (r=0,242, r2=0,059), dan moderat dengan TPC (r=0,300, r2=0,090). Faktor lain yang memengaruhi produksi dan kualitas susu sapi perah di KPSBU Lembang adalah genetik, kesehatan hewan dan manajemen kandang. Disimpulkan, curah hujan bukan faktor utama yang memengaruhi produksi dan kualitas susu sapi FH di KPSBU Lembang tahun 2022., Friesian Holstein cattle milk production in Indonesia is lower than its origin, Netherlands. Milk production and quality is affected by many factors such as genetic, cattle’s health, and environment aspect including rainfall. This study aims to determine the correlation of milk production and quality with rainfall in KPSBU Lembang in 2022. Milk production and quality data were collected from KPSBU Lembang and rainfall data were collected from BMKG Jawa Barat. The collected data were analyzed by two tests, correlation test to prove the correlation closeness, and regression tests to show the determinant coefficient (r2) or effect percentage of rainfall on milk production and quality. Rainfall has a very weak correlation with milk production (r=0,044, r2=0,002), while milk quality is correlated to rainfall in various category; weak with fat content (r=0,118, r2=0,14),very weak with total protein (r=0,010, r2=0,001), weak with density (r=0,242, r2=0,059), and moderate with total plate count (r=0=,300, r2=0,090). In conclusion, rainfall is not the main factor affecting the production and quality of FH cow's milk at KPSBU Lembang in 2022.
Keyword: Friesian holstein, Milk production, Milk quality, Rainfall

Judul: Pengaruh Keragaman Iklim terhadap Produksi Susu Sapi Perah Fries Holland (Studi Kasus: UPTD BPT SP & HMT Cikole)
Abstrak: Rainfall variability during dry and rainy season affect variation in milk production at UPTD BPT SP & HMT Cikole in Lembang, West Java. Milk production rate during the dry season is higher compared to the rainy season. This is due to the quality of food consumed by the cows during the dry season is better than the rainy season. Analysis between rainfall data and milk production using linear regression analysis produces a relatively strong relationship shown by determination coefficient equal to 0,919, showing that the rainfall variability explains more than 90% of milk production. Distribution and variability of rainfall in Indonesia is influenced by El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) event, where both phenomena can be identified by using Ocean Nino Index (ONI) and Dipole Mode Index (DMI), respectively. Compared to DMI, ONI has a stronger relationship withrainfall and milk production at UPTD BPT SP & HMT Cikole, Lembang. ONI can be used to predict milk production in the rainy season and the dry season with a time lag of three months. The prediction model for milk production in the dry season is developed by using milk production data in JJA and rainfall data in MAM. For the rainy season, the prediction model uses pair of milk production data in DJF and rainfall data in SON.The relationship between seasonal ONI and milk production indicate a quadratic pattern, with a coefficient of determination around 92.8% and 34.3% in the rainy and dry season, respectively.
Keyword: Rainfall, ONI, DMI, Milk Production, Cow Fries Holland

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf