Judul: The Effect of Work Discipline and Work Motivation on Employee Performance at the Balangan Coal Mining Company
Abstrak: Pertambangan menjadi salah satu lapangan usaha yang menyumbang pertumbuhan ekonomi Indonesia. Balangan Coal merupakan sebuah perusahaan tambang batu bara yang berada di Balangan, Kalimantan Selatan yang memiliki misi untuk mengembangkan sumber daya manusia yang kompeten dan profesional. Pada perusahaan tambang Balangan Coal disiplin kerja dan motivasi kerja karyawan masih kurang. Tujuan dari penelitian ini adalah menganalisis pengaruh disiplin kerja dan motivasi kerja terhadap kinerja karyawan di perusahaan tambang Balangan Coal. Pendekatan yang dilakukan adalah dengan metode kuantitatif dan teknik pengumpulan data menggunakan kuesioner yang diberikan kepada karyawan Balangan Coal. Pengambilan sampel menggunakan metode non-probability sampling dengan teknik purposive sampling yaitu karyawan yang telah bekerja diatas 1 tahun. Jumlah sampel yang diteliti adalah 65 karyawan. Analisis data yang digunakan adalah dengan metode SEM-PLS. Hasil pengujian menyatakan bahwa disiplin kerja tidak memiliki pengaruh positif dan signifikan terhadap kinerja karyawan, motivasi kerja memiliki pengaruh positif dan signifikan terhadap kinerja karyawan, dan disiplin kerja memiliki pengaruh positif dan signifikan terhadap motivasi kerja., Mining has become one of the business sectors contributing to Indonesia's economic growth. Balangan Coal is a coal mining company located in Balangan, South Kalimantan, with a mission to develop competent and professional human resources. In Balangan Coal mining company, both work discipline and employee motivation are lacking. The purpose of this study is to analyze the influence of work discipline and work motivation on employee performance at Balangan Coal mining company. The approach used is quantitative method, and data collection technique involves distributing questionnaires to Balangan Coal employees. Sample selection was done using non-probability sampling method with purposive sampling technique, targeting employees who have worked for more than 1 year. The total sample size studied was 65 employees. The data analysis method used is Structural Equation Modeling-Partial Least Squares (SEM-PLS). The results showed that work discipline did not have a positive and significant influence on employee performance, work motivation had a positive and significant influence on employee performance, and work discipline had a positive and significant influence on work motivation.
Keyword: Employee Performance, Work Discipline, Work Motivation

Judul: The effect of working capital management components to the profitability of mining sector company in indonesia stock exchange
Abstrak: Pertambangan menjadi salah satu penentu perekonomian Indonesia karena berperan strategis dan berpengaruh besar terhadap hajat hidup orang banyak. Hal tersebut tentunya menuntut perusahaan pertambangan agar mampu berproduksi secara optimal termasuk mengelola modal kerja dengan baik yang nantinya akan berdampak pada profitabilitas. Penelitian ini menggunakan laporan keuangan tahun 2012-2013 seluruh perusahaan yang tergabung ke dalam sektor pertambangan dan terdaftar di Bursa Efek Indonesia (BEI) dengan menggunakan analisis rasio keuangan dan analisis regresi linier berganda sebagai metode penelitian. Variabel independen dalam penelitian ini adalah komponen manajemen modal kerja yang terdiri dari cash conversion cycle (CCC), average collection period (ACP), average age of inventory (AAI), dan average payment period (APP). Sedangkan variabel dependen dalam penelitian ini adalah profitabilitas yang diproksikan oleh net profit margin (NPM). Hasil analisis secara simultan maupun parsial menunjukkan bahwa komponen manajemen modal kerja tidak berpengaruh terhadap profitabilitas perusahaan sektor pertambangan di BEI., Mining sector has become one of those which determines Indonesia’s economy due to the strategic role and has a big power of impact to many peoples. So that mining company has to produce optimal and manage the working capital properly consider to the profitability. This research using 2012-2013 financial report of all the mining sector companies in Indonesia Stock Exchange with financial ratio analysis and multiple linear regression analysis as the research method. The independent variable in this research is working capital management components that are consist of cash conversion cycle (CCC), average collection period (ACP), average age of inventory (AAI), dan average payment period (APP). The dependent variable is profitability that is proxy by net profit margin (NPM). The result simultaneously and partially is working capital management components don’t have any impact to the profitability of mining sector companies in Indonesia Stock Exchange.
Keyword: komponen manajemen modal kerja, profitabilitas, perusahaan pertambangan, bursa efek indonesia

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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