The New Superfluid Helium Cryostats for the Short Straight Sections of the CERN Large Hadron Collider (LHC)

The lattice of the CERN Large Hadron Collider (LHC) contains 364 Short Straight Section (SSS) units, one in every 53 m long half-cell. An SSS consists of three major assemblies: the standard cryostat section, the cryogenic service module, and the jumper connection. The standard cryostat section of an SSS contains the twin aperture high-gradient superconducting quadrupole and two pairs of superconducting corrector magnets, operating in pressurized helium II at 1.9 K. Components for isolating cryostat insulation vacuum, and the cryogenic supply lines, have to be foreseen. Special emphasis is given to the design changes of the SSS following adoption of an external cryogenic supply line (QRL). A jumper connection connects the SSS to the QRL, linking all the cryogenic tubes necessary for the local full-cell cooling loop [at every second SSS]. The jumper is connected to one end of the standard cryostat section via the cryogenic service module, which also houses beam diagnostics, current feedthroughs, and instrumentation capillaries. The conceptual design fulfilling the tight requirements of magnet alignment precision and cryogenic performance are described. Construction details, aimed at minimizing costs of series manufacturing and assembly, while ensuring the high quality of this complex accelerator component, are given

A Modular Design for the 56 Variants of the Short Straight Section in the Arcs of the Large Hadron Collider (LHC)

The 360 Short Straight Sections (SSS) necessary for the eight arcs of the LHC machine have to fulfil different requirements. Their main function is to house the lattice two-in-one superconducting quadrupole and various correction magnets, all operating at 1.9 K in a superfluid helium bath. The magnetic and powering schemes of the arcs and the fact that the two proton beams alternate between the inner and outer magnet channels impose 24 different combinations of magnet assemblies, all housed in an identical helium enclosure. The cryogenic architecture of the LHC machine is based on cryogenic loops spanning over one half-cell (53 m) for the 4.6-20 K circuit, over a full cell (107 m) for the 1.9 K circuits, up to the full arc (about 2.3 km) for the shield cooling line. This cryogenic layout, when superimposed to the magnetic scheme, further complicated by the cryostat insulation vacuum sectorisation every 2 cells, creates additional assembly variants, up to a total number of 56. The required flexibility in the manufacture and assembly, as well as economic considerations, have led to a modular design for the different SSS components and sub-assemblies. This modularity allows to "specialise" the SSS at the latest possible assembly step of the "just in time" production line. This paper presents the conceptual design considerations to achieve this modularity, the SSS design retained for the series manufacture, and the assembly procedures recently validated on a prototype program at CERN

Optimized parameter search for large datasets of the regularization parameter and feature selection for ridge regression

In this paper we propose mathematical optimizations to select the optimal regularization parameter for ridge regression using cross-validation. The resulting algorithm is suited for large datasets and the computational cost does not depend on the size of the training set. We extend this algorithm to forward or backward feature selection in which the optimal regularization parameter is selected for each possible feature set. These feature selection algorithms yield solutions with a sparse weight matrix using a quadratic cost on the norm of the weights. A naive approach to optimizing the ridge regression parameter has a computational complexity of the order with the number of applied regularization parameters, the number of folds in the validation set, the number of input features and the number of data samples in the training set. Our implementation has a computational complexity of the order . This computational cost is smaller than that of regression without regularization for large datasets and is independent of the number of applied regularization parameters and the size of the training set. Combined with a feature selection algorithm the algorithm is of complexity and for forward and backward feature selection respectively, with the number of selected features and the number of removed features. This is an order faster than and for the naive implementation, with for large datasets. To show the performance and reduction in computational cost, we apply this technique to train recurrent neural networks using the reservoir computing approach, windowed ridge regression, least-squares support vector machines (LS-SVMs) in primal space using the fixed-size LS-SVM approximation and extreme learning machines

IMPLEMENTASI PEMBERIAN GANTI KERUGIAN LAYANAN PAKET DI PT TIKI JALUR NUGRAHA EKAKURIR (JNE) CABANG SURAKARTA DITINJAU DARI UNDANG-UNDANG NOMOR 38 TAHUN 2009 TENTANG POS

ABSTRAK Yusuf Bintang Syaifinuha, E0012414. 2016. IMPLEMENTASI PEMBERIAN GANTI KERUGIAN LAYANAN PAKET DI PT TIKI JALUR NUGRAHA EKAKURIR (JNE) CABANG SURAKARTA DITINJAU DARI UNDANG-UNDANG NOMOR 38 TAHUN 2009 TENTANG POS. Fakultas Hukum Universitas Sebelas Maret Surakarata. Penelitian ini bertujuan untuk mengetahui implementasi pemberian ganti kerugian di PT Tiki Jalur Nugraha Ekakurir (JNE) Cabang Surakarta ditinjau dari UU Pos dan untuk mengetahui cara penyelesaian sengketa yang timbul dari implementasi pemberian ganti kerugian di PT Tiki Jalur Nugraha Ekakurir (JNE) Cabang Surakarta. Metode penelitian yang digunakan dalam penelitian ini adalah deskriptif kualitatif. Jenis penelitian ini adalah penelitian empiris. Data yang digunakan terdiri dari dua data yaitu data primer dan data sekunder. Teknik pengumpulan data adalah dengan metode wawancara dan studi pustaka. Berdasarkan hasil analisis penelitian, dapat diambil kesimpulan bahwa implementasi pemberian ganti kerugian di JNE kurang sesuai dengan Pasal 28 UU Pos karena jenis ganti kerugian hanya untuk kehilangan kiriman dan kerusakan isi kiriman. Pengirim yang mengajukan klaim ganti kerugian harus memenuhi syarat administrasi yang telah ditetapkan oleh JNE. Nilai ganti kerugian yang diberikan JNE adalah 10 kali biaya pengiriman atau sesuai harga barang yang hilang dan/atau rusak jika menggunakan asuransi. JNE memilih upaya hukum diluar pengadilan (nonlitigasi) berupa negosiasi dalam menyelesaikan sengketa yang terjadi dalam implementasi pemberian ganti kerugian. Kata kunci :Perjanjian, Wanprestasi, Implementasi ganti kerugian

Gerbera cultivation on coir with recirculation of the nutrient solution : a comparison with rockwool culture

An experiment with Gerbera 'Aurelia' was set up to evaluate flower production and flower stem quality in an open and a closed growing system. For both systems two substrates, coir and rockwool, were evaluated. No major differences were detected between the nutrient composition of the drainage water for both cultivation systems and both substrates. Re-use of the drainage water resulted in fertilizer savings of +/- 35 %. No differences in flower production and in flower quality were found with re-use of the drainage water in comparison with an open drain system. The choice of the substrate however, influenced the flower quality but not the number of flowering stems. For Gerbera 'Aurelia' grown on coir the flowering stems were periodically shorter than for plants grown on rockwool, yet flower stem weight was superior for plants grown on coir than for those grown on rockwool