Judul: Analysis of Okiagaru Indonesia Cooperative Performance
Abstrak: Koperasi merupakan suatu alat bagi pembangunan perekonomian suatu bangsa. Koperasi memiliki orientasi untuk kesejahteraan anggotanya dibandingkan keuntungan perseorangan. Koperasi Okiagaru Indonesia Agricoop merupakan koperasi yang berdiri pada Mei 2019. Koperasi Okiagaru merupakan koperasi pemasaran agribisnis dengan anggota yang tersebar di seluruh wilayah Indonesia. Hal ini menyebabkan perlunya dilakukan analisis terhadap kinerja koperasi. Analisis kinerja koperasi dilakukan berdasarkan perspektif pengurus dan anggota. Penilaian Tangga Perkembangan (PTP) digunakan untuk menilai kinerja koperasi berdasarkan perspektif pengurus, sementara analisis deskriptif antara kualitas pelayanan dan manfaat sosio-ekonomi digunakan untuk menilai kinerja koperasi berdasarkan perspektif anggota. Analisis kinerja koperasi menggunakan PTP menunjukkan hasil yang baik secara keseluruhan, namun dengan catatan perbaikan pada indikator sumberdaya. Koperasi Okiagaru telah memberikan pelayanan yang baik, dibuktikan melalui kecepatan, ketepatan dan pengetahuan pelayanan, serta pemberian rasa aman dan kemampuan berkomunikasi pengurus. Koperasi juga berhasil memberikan kebermanfaatan secara sosial dan ekonomi kepada anggotanya. Keberhasilan dalam pelayanan dan manfaat sosial ekonomi ini memberikan kepuasan kepada anggota yang dibuktikan dengan hubungan yang positif secara signifikan pada selang kepercayaan 95% antara partisipasi dan kualitas pelayanan serta manfaat sosio-ekonomi. Hubungan yang positif ini memudahkan koperasi dalam mewujudkan visinya, serta mempengaruhi keberhasilan kinerja koperasi., Cooperative is a tool for national economic development. Cooperative has an orientation for the welfare of their members rather than individual profits. Okiagaru Indonesia Agricoop Cooperative is a cooperative that was established in May 2019. Okiagaru Cooperative is an agribusiness marketing cooperative with members spread throughout Indonesia. This causes the need to analyze the performance of cooperatives. The Development Ladder Assessment (DLA) was used to assess cooperative performance based on the management, while descriptive analytics between services quality and socio-economic benefits were used to assess based on the perspective of members. The results showed that this study successfully identified the profile of Okiagaru Cooperative. Analysis of the cooperative's performance using PTP showed good results overall, but with a note of improvement on the resource indicators. The cooperative has provided good service, as evidenced by the speed, accuracy and knowledge of the service, as well as providing a sense of security and the ability to communicate with the management. The cooperative has also succeeded in providing social and economic benefits to its members. The success in service and socio-economic benefits provides satisfaction to members, which is proved by the significantly positive in confidence interval of 95% relation between member participation and services quality and socio-economic benefits. This positive relation makes it easier for the cooperative to realize its vision, and affects the success of the cooperative's performance.
Keyword: Agribusiness, marketing cooperative, member participation, service quality, sosio-economy benefit

Judul: Performance Measurement of Koperasi Serba Usaha Karya Nugraha Jaya with Balanced Scorecard approach
Abstrak: Umumnya pengukuran kinerja pada koperasi bergantung hanya pada aspek keuangannya saja. Pentingnya pengukuran kinerja secara menyeluruh baik secara internal maupun eksternal menjadi latar belakang Koperasi Serba Usaha Karya Nugraha Jaya untuk diukur kinerjanya. Penelitian ini bertujuan untuk mengukur kinerja koperasi dengan menggunakan pendekatan balanced scorecard. Pengambilan data didapatkan dengan wawancara langsung dan pengisian kuesioner. Hasil penelitian menunjukkan bahwa karyawan, peternak dan pengurus koperasi sudah berkolaborasi dengan baik. Pengukuran kinerja Koperasi Serba Usaha Karya Nugraha Jaya menunjukkan predikat baik dan sangat baik, perspektif keuangan mendapatkan nilai 18,1%, perspektif bisnis internal dengan nilai 23,9%, perspektif pelanggan dengan nilai 23,6%, dan perspektif pertumbuhan dan pembelajaran dengan nilai 19,8%. Secara menyeluruh kinerja koperasi mendapatkan nilai 85,5% dan mendapatkan predikat sangat baik dengan label berwarna biru., Performance measurement of a cooperative are generally assessed from a financial perspective only. The importance of measuring the overall performance of both internal and external, became the chosen background of this research. This research has objective to identify measure performance cooperative with balanced scorecard approach. Data retrieval were carried out with direct interviews and filling out the questionnaire. The result showed that the cooperative employee, breeders and management have clear collaboration. The measurement of cooperative performance shows get good and excellent predicate, the financial perspective has a value of 18.1%, the internal business perspective got value of 23.9%, the customer perspective got value of 23.6%, and the perspective of growth and learning got value of 19.8%. Overall cooperative performance got a value 85.5% and got the predicate very well or blue color card.
Keyword: balanced scorecard, cooperative performance, KSU Karya Nugraha Jaya

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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