Judul: Perbandingan Metode K-Means, K-Medoids, dan Hierarki untuk  Penggerombolan Kabupaten/Kota di Sumatera Utara Berdasarkan  Jenis Kekerasan terhadap Perempuan
Abstrak: Kekerasan adalah perbuatan yang dilakukan dengan sengaja oleh seseorang atau kelompok dengan tujuan menindas yang lemah agar menderita. Salah satu penyebabnya adalah tingginya angka depresi yang berujung pada tindakan kekerasan terhadap orang-orang di sekitarnya, termasuk perempuan. Penelitian ini bertujuan membandingkan penggerombolan kabupaten/kota di Sumatera Utara berdasarkan jenis kekerasan terhadap perempuan menggunakan metode K-Means, K-Medoids, dan Metode Hierarki, serta melihat karakteristik persebaran wilayah dari hasil penggerombolan yang diperoleh. Penelitian ini menggunakan data banyaknya korban kekerasan terhadap perempuan tahun 2021 yang bersumber dari Sistem Informasi Online Perlindungan Perempuan dan Anak dan Badan Pusat Statistik Sumatera Utara yang terdiri dari 33 kabupaten/kota dan enam peubah. Evaluasi hasil penggerombolan menggunakan Davies Bouldin Index dan Korelasi Cophenetic. Metode analisis gerombol optimal yang diperoleh adalah K-Medoids dengan banyaknya gerombol sebanyak 4. Gerombol 1 memiliki nilai rataan yang paling rendah setiap jenis kekerasan. Gerombol 2 memiliki nilai rataan pada jenis kekerasan fisik yang lebih tinggi dibandingkan dengan rataannya. Gerombol 3 memiliki nilai rataan pada jenis kekerasan psikis, perdagangan orang, dan penelantaran yang lebih tinggi dibandingkan dengan rataannya. Gerombol 4 memiliki nilai rataan yang paling tinggi pada setiap jenis kekerasan kecuali perdagangan orang dibandingkan dengan rataannya., Violence is an act that is intentionally by a person or group with the aim of oppressing someone to suffer. The high rate of depression which leads to acts of violence against those around them, including women. This study aims to compare the clustering of districts/cities in North Sumatra based on the type of violence against women using the K-Means, K-Medoids, and Hierarchical Methods, and look at the characteristics of the regional distribution of the clustering results. This study uses data the number of victims of violence against women in 2021 from Sistem Informasi Online Perlindungan Perempuan dan Anak and Badan Pusat Statistik Sumatera which consists of 33 districts/cities and six variables. Evaluation of clustering results using the Davies Bouldin Index and Cophenetic Correlation. The optimal cluster analysis method obtained is K-Medoids with 4 clusters. Cluster 1 has the lowest average value for each type of violence. Group 2 has an average value of physical violence that is higher than the average. Group 3 has a higher average score for the types of psychological violence, trafficking, and neglect than the average. Cluster 4 had a highest average score for each type of violence except trafficking than the average.
Keyword: cophenetic correlation, Davies Bouldin Index, hierarchical clustering, non-hierarchical clustering, violence

Judul: Comparison of K-Medoid and Robust Sparse K-Means for Clustering Provinces in Indonesia Based on Crime Indicators
Abstrak: Kriminalitas adalah tindakan melanggar hukum yang dilakukan dengan sadar dan sengaja untuk menguntungkan diri sendiri dan merugikan orang lain. Pada tahun 2021, Indonesia menempati peringkat 72 dari 142 negara di dunia dengan indeks kriminalitas sebesar 46,23. Semakin tinggi tingkat kriminalitas pada suatu daerah, semakin banyak kejahatan yang terjadi sehingga menyebabkan masyarakat kehilangan rasa aman. Banyak kejahatan provinsi di Indonesia beragam yang menunjukkan adanya kesenjangan akan keamanan. Kesenjangan banyak kejahatan antarprovinsi menimbulkan pencilan pada beberapa daerah. Tujuan penelitian adalah menggerombolkan provinsi berdasarkan indikator kriminalitas dengan memerhatikan pencilan menggunakan K-Medoid dan Robust Sparse K-Means. Data yang digunakan pada penelitian ini berasal dari 34 provinsi dengan 16 peubah numerik indikator kriminalitas tahun 2021. K-Medoid menghasilkan empat gerombol optimal dengan banyak anggota dari masing-masing gerombolnya adalah 22, 4, 1, dan 7. Gerombol 1, 2, dan 3 dikategorikan sebagai daerah dengan angka kejahatan rendah. Gerombol 3 merupakan daerah dengan kepadatan penduduk dan PDRB tinggi ekstrem dibandingkan gerombol lain. Gerombol 4 dikategorikan sebagai daerah dengan angka kejahatan sangat tinggi. Hasil penggerombolan optimum ditentukan berdasarkan rasio sw⁄sb minimum. K Medoid lebih baik dibandingkan RSK-Means karena memiliki rasio sw⁄sb lebih kecil., Crime is an unlawful act carried out consciously and deliberately to benefit oneself and harm others. In 2021, Indonesia was ranked 72 out of 142 countries in the world with a crime index of 46,23. The higher the crime rate in an area, the more crimes that occur, causing people to feel insecure. The number of crimes per province in Indonesia varies, showing a gap in security. This range of variation leads to an extreme crime rate index or outliers in some areas. The aim of this study is to cluster provinces based on crime indicators by paying attention to outliers using K Medoid and Robust Sparse K-Means. The data used in this study were from 34 provinces with 16 numerical variables of crime indicators in 2021. K-Medoid produces four optimal clusters with the number of members in each cluster being 22, 4, 1, and 7. Clusters 1, 2, and 3 are categorized as areas with a low crime rate. Cluster 3 is an area with an extremely high population density and GRDP compared to other clusters. Cluster 4 is categorized as an area with a very high crime rate. The best clustering results are determined based on the minimum sw⁄sb ratio. K Medoid has better performance than RSK Means with a smaller sw⁄sb ratio.
Keyword: gerombol, kriminalitas, k-medoid, pencilan, robust sparse k-means

Judul: Utilization of hydrolized duckweed (Lemna minor) meal as a soybean replacement in Nile tilapia (Oreochromis niloticus) diet,
Abstrak: Tilapia is a fast growing fish widely cultured in many tropical and sub tropical countries. The recent production figures reported our global production estimates for 2015 is 5,576.8 metric tons. In developing countries the major challenges facing aquaculture industry is high cost of production associated with fish feeds. Feed represents 40-70% of operating costs for aquaculture operations, increasing expenses and potential declining supplies soybean meal have led scientists to search for less expensive but compatible alternative protein sources for fish feed; most of which are based on animal or plant protein sources. The objectives of study was to determine the incubation period for hydrolysis of duckweed and to evaluate the use of hydrolized duckweed as aprotein source for the growth performance of Nile tilapia Three experiments were conducted to determine the composition and digestibility of hydrolyzed duckweed meal by sheep rumen liquor as the replacement of soybean meal in the diet of Nile tilapia. The first trial examined the effectivity of sheep rumen liquor enzyme to decrease crude fiber contents of (DWM), the added volume of sheep rumen liquor was 100 ml/kg DWM and then it was incubated for 0, 12, 24 hr . The second trial was to evaluate the apparent digestibility of hydrolyzed DWM for Nile Tilapia, apparent digestibility were determined using chromic oxide indicator added to both reference diet and test diets. The feed ingredients used in the trial were hydrolyzed DWM (HDWM) and unhydrolyzed DWM (DWM). Ten fish with an average weight of 18±0.36g were used in the trial and reared in the aquarium of size 30×40×50cm for 15 days; feces were collected from three replicates using a fecal collection column attached to the aquarium. Third trial was to evaluate the growth performance of Tilapia fed test diet with hydrolyzed Duckweed meal (HDWM). The experimental design was set according to completely randomized design with four treatments and three replicates of HDWM inclusion levels that is 0%, 15%, 30% and 45%. Nile tilapia fish with initial body weight of 18±0.36g was kept in 12 units aquarium size of 30×40×50cm at stocking density of 10fish/aquarium, the fish were fed two times a day at 08:00am and 16:00pm to apparent satiation for a period of 60 days. The results indicated that duckweed meal (DWM) hydrolyzed with 100 mL/kg and incubated for 24 hrs showed the lowest crude fiber contents of 13.68% compared to other treatments. Total digestibility of hydrolyzed duckweed (HDWM) meal was 87.3% compared with unhydrolyzed duckweed (DWM) which was 66.8%. Total final weight (TFW), survival rate (SR), specific growth rate (SGR), feed conversional rate (FCR) and protein retention (PR) shows growth performance at 15% inclusion. The results of this study showed that 100mL/kg sheep rumen liquor at incubation period of 24 hr can be suitable for hydrolysis of duckweed to reduce crude fiber also hydrolyzed duckweed can substitute soybean meal at an incubation rate of 15% in the diet of Nile tilapia and had the same growth and FCR with control diet
Keyword: Digestibility, Duckweed meal, Growth performance, Sheep rumen