Judul: Modeling the Diversity of Food Security Index in Indonesia with Spatial Approach, Efficiency Analysis, and Clustering
Abstrak: Ketahanan pangan yang digambarkan oleh ukuran Indeks Ketahanan Pangan (IKP) umumnya memiliki variasi permasalahan regional antar wilayahnya dan cenderung berfluktuasi antar tahunnya, sehingga diperlukan pendekatan penanganan yang disesuaikan dengan kondisi masing-masing wilayah. Penelitian ini menggunakan pendekatan geographically temporally weighted regression yang memungkinkan untuk memodelkan keragaman spasial dan temporal dalam data, dan sesuai dengan sifat data ketahanan pangan yaitu cenderung bervariasi antar wilayah dan tahun. Selanjutnya output analisis tersebut diperdalam dengan data envelopment analysis untuk menilai efisiensi pemanfaatan sumber daya terhadap kondisi ketahanan pangan antar wilayah dan menggunakan penggerombolan k-medoid untuk melakukan perbandingan kondisi pangan antar kelompok wilayah. Seluruh wilayah di Indonesia menjadi objek penelitian ini, yaitu sebanyak 514 kabupaten/kota selama tahun 2020-2022. Hasil dari penelitian menunjukkan bahwa peubah angka harapan hidup, laju pertumbuhan penduduk, persentase penduduk miskin, produksi tanaman pangan, dan pengeluaran per kapita berpengaruh pada taraf nyata 5% terhadap nilai IKP di sebagian besar wilayah, dengan nilai Pseudo R^2 sebesar 91.2%. Hasil analisis DEA menunjukkan terdapat dua puluh tujuh daerah di Indonesia yang selalu konsisten dengan tingkat efisiensi ketahanan pangan maksimum. Namun secara keseluruhan, kemampuan efisiensi mengalami penurunan yang cukup signifikan pada tahun 2022. Hal ini diperkuat dengan hasil analisis gerombol k-medoid bahwa dari tiga gerombol yang terbentuk (gerombol dengan IKP cenderung tinggi, sedang, dan rendah), gerombol dengan tingkat ketahanan pangan rendah mengalami peningkatan sebesar 9% dari tahun 2020 ke tahun 2022 yang perlu diperhatikan., Food security, which is represented by the Food Security Index (FSI) measure, generally has regional variations between regions and tends to fluctuate between years, so a handling approach that is tailored to the conditions of each region is needed. This study uses a geographically temporally weighted regression approach that allows to model spatial and temporal variability in the data, which is in accordance with the nature of food security data, which tends to vary between regions and years. Then the output of the analysis is deepened with data envelopment analysis to assess the efficiency of resource utilization towards food security conditions between regions and using k-medoid clustering to compare food conditions between regional groups. All regions in Indonesia became the object of this research, namely 514 districts/cities during 2020-2022. The results of the study indicated that the variables of life expectancy, population growth rate, percentage of poor people, food crop production, and per capita expenditure have a significant effect on the FSI value in most regions, with a Pseudo R^2 value of 91.2%. The results of DEA analysis showed that there are twenty seven regions in Indonesia that are always consistent with the maximum level of food security efficiency. But overall, the efficiency ability has decreased significantly in 2022. This is reinforced by the results of the k-medoid clustering analysis that of the three clusters formed (clusters with IKP tending to be high, medium, and low), the cluster with a low level of food security has increased by 9% from 2020 to 2022, which needs more attention.
Keyword: data envelopment analysis, food security index, geographically temporally weighted regression, k-medoid clustering

Judul: Mapping and Spatial Analysis of the Determinants of Food Security in Indonesia 2023
Abstrak: Sepanjang dibentuknya indeks ketahanan pangan (IKP) dari 2018, tercatat terjadi fluktuasi. Skor ketahanan pangan paling baik dicapai pada 2023. Secara umum, Indonesia bagian timur cenderung memiliki ketahanan pangan yang rendah, mengindikasikan variasi antara satu dengan lainnya. Penelitian ini bertujuan menganalisis kondisi ketahanan pangan Indonesia dan determinan yang memengaruhinya. Data yang digunakan meliputi pertumbuhan penduduk, produksi beras, harga beras, pengeluaran konsumsi beras, serta kecukupan konsumsi gizi dari 34 provinsi di Indonesia pada tahun 2023. Metode yang digunakan meliputi analisis statistik deskriptif dan regresi dengan pendekatan Spatial Autoregressive Combined (SAC). Hasil pemetaan menunjukkan bahwa terdapat variasi ketahanan pangan berdasarkan aspek utama dan turunannya. Kemudian, analisis regresi spasial memberikan hasil bahwa limpahan spasial signifikan, menunjukkan keterkaitan antarwilayah dalam ketahanan pangan. Produksi beras dan kecukupan konsumsi gizi berpengaruh signifikan meningkatkan ketahanan pangan, sedangkan pertumbuhan penduduk berpengaruh signifikan menurunkan ketahanan pangan., Throughout the establishment of the food security index (IKP) from 2018, there have been fluctuations. The best food security score was achieved in 2023. In general, the eastern part of Indonesia tends to have low food security, which shows the fluctuations from one region to another. This study aims to analyze the state of food security in Indonesia and the determinants that affect it. The data used include population growth, rice production, rice price, rice consumption expenditure, and food consumption from 34 provinces in Indonesia in 2023. The methods used include descriptive statistical analysis and Spatial Autoregressive Combined (SAC) regression. The mapping results show that there are variations in food security based on the main aspects and their derivatives. Then, the spatial regression analysis shows that spatial spillovers are significant, indicating inter-regional linkages in food security. Rice production and food consumption have a significant effect on improving food security, while population growth has a significant effect on reducing food security.
Keyword: Beras, ketahanan pangan, Food security, rice, spatial, efek langsung, efek tidak langsung, spasial, direct effects, indirect effects

Judul: Hydrothermal Synthesis of Biphasic Calcium Posphate
Abstrak: Biphasio calsium phosphate (BCP), which was a mixture of hydroxypatite (HA) and tricalcium phosphate (TCP), was synthesized by hydrothermal method followed by sintering process. Hydroxyapatite was produced by using natural calcium source CaO from hen's eggshell and (NH4)2HPO4 as phosphate souce, other hydroxyapatite sample was produce by using synthetic calcium source Ca(OH) and H3PO4 as phosphate source.
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