EFEK DAYA LEDAK OTOT TUNGKAI DAN MOTIVASI BERPRESTASI DALAM KETERAMPILAN SMASH PADA ATLET BOLA VOLI

Tujuan Penelitian. Untuk mengetahui Pengaruh daya ledak otot tungkai dan motivasi berprestasi  terhadap keterampilan smash bola voli pada Atlet Bola Voli Putra Klub Huha Pekanbaru Metode Penelitian. Metode penelitian yang digunakan dalam penelitian ini adalah pendekatan kuantitatif, metode survei dengan teknik pengukuran dan tes. Sedangkan teknik analisis menggunakan pendekatan analisis jalur (path analysis) yaitu penelitian yang akan mengkaji atau menganalisis keterkaitan antar variabel penelitian. Hasil. 1) Terdapat pengaruh  langsung daya ledak otot (X1) terhadap hasil Keterampilan Smash Bola Voli (Y) sebesar 0,331. 2) Terdapat pengaruh  langsung Motivasi Berprestasi (X2) terhadap hasil Keterampilan Smash Bola Voli (Y) sebesar 0,291. Hal ini terlihat pada Tabel Coffesient yang menunjukan nilai sig. 0,001. 3) Terdapat pengaruh langsung Daya Ledak Otot (X1) terhadap motivasi berprestasi (X2) sebesar 0,370. Hal ini terlihat pada Tabel Coffesient yang menunjukan nilai sig. 0,000. Dan pengaruh total X1 dan X2 terhadap Y sebesar 0,476 = 47,60%. Kesimpulan. Daya ledak otot dan motivasi berprestasi berpengaruh terhadap keterampilan smash bola voli atlet Putra Klub Huha Pekanbaru.The purpose of the study. The purpose of this study was to determine the effect of lexplosive power leg and achievement motivation on volleyball smash skills at Club Ball Volleyball Athlete Huha Pekanbaru. Materials and methods. The research method used in this research is quantitative approach, survey method with measurement and test techniques. While the analytical technique using path analysis approach (path analysis) is research that will examine or analyze the relationship between research variables. Path analysis technique can be used to test the direct influence on the influence factor of explosive power leg, hand eye coordination and achievement motivation on smash volleyball skills from 34 athletes Putra Klub Huha Pekanbaru Results. 1) There is direct influence of explosive power leg (X1) on the result of the Volleyball Smash Skill (Y) of 0.331. This is seen in Table Coffesient which shows the sig value. 0.005  (Significant). 2) There is a direct influence of Achievement Motivation (X2) on the result of  mash Volleyball skill (Y) of 0.291. 3) There is direct influence of explosive power leg (X1) on achievement motivation (X2) equal to 0,370. This is seen in Table Coffesient which shows the sig value. 0,000. (Significant). And total efect  of X1, X2 terhadap Y sebesar 0,476 = 47,60%. Conclusions. The effect of explosive power leg, hand eye coordination and achievement motivation affect the skills of smash volleyball athletes Club Huha Pekanbaru

Strategi Komunikasi Pemkot Depok Dalam Kampanye 3R Melalui Bank Sampah Menuju Lingkungan Yang Bersih Dan Sehat

The research objective is to explain and evaluate the Depok City Government's communication strategy in the 3R campaign through the Waste Bank to create a clean and healthy environment. This research uses a qualitative approach with a case study design to explore the Depok City Government's communication strategy in the 3R campaign through the Waste Bank. Primary data was obtained through in-depth interviews and FGDs with City Government officials, Waste Bank managers and the community, while secondary data was taken from official documents and media publications. Data was analyzed using thematic analysis techniques to identify key themes, patterns and relevant relationships, providing a comprehensive picture of the success of the 3R campaign in Depok. The result of this work is that the Depok community's awareness of the importance of 3R has increased significantly with active participation in seminars, workshops and training organized by the Depok City Government. The effectiveness of the Waste Bank and the use of social media and information technology has succeeded in reducing the amount of waste in landfills and empowering the community in managing household waste. Collaboration between the City Government, the private sector and local communities through CSR support and active participation of environmental communities has had a positive impact. Regular evaluation and improvement of infrastructure is a priority for the Depok City Government, with incentives and rewards to encourage community participation, ensuring the sustainability of the 3R program

KOMUNIKASI ANTARPRIBADI PEMANDU MUSEUM PADA LAYANAN VIRTUAL TOUR MUSEUM KEHUTANAN MELALUI APLIKASI ZOOM

Museum Kehutanan merupakan destinasi wisata di Jakarta yang dikelola Kementerian Lingkungan Hidup dan Kehutanan. Pandemi yang melanda selama dua tahun membuat Museum Kehutanan mengadaptasi layanan publik dengan menggunakan teknologi komunikasi kekinian, yakni virtual tour dengan memanfaatkan aplikasi zoom. Interaksi sosial dan komunikasi antarpribadi yang terbangun dalam layanan virtual tour antara Pemandu Museum Kehutanan selaku Komunikator dan Para peserta Layanan Virtual Tour sebagai Komunikan menarik untuk diteliti. Tujuan penelitian ini adalah memahami dan menjelaskan peran komunikasi antarpribadi Pemandu Museum dalam layanan virtual tour Museum Kehutanan melalui aplikasi zoom. Penelitian ini menggunakan metode deskriptif kualitatif dengan desain studi kasus di Museum Kehutanan. Hasil penelitian menunjukan bahwa Pemandu Museum Kehutanan dalam proses interaksi sosial dan komunikasi antar pribadi melakukan pendekatan sesuai teori DeVito, yakni keterbukaan, empati, sikap mendukung, sikap positif dan kesetaraan, agar kegiatan virtual tour tidak membosankan dan berkesan bagi Peserta untuk datang berkunjung secara langsung di Museum Kehutanan. Respon peserta virtual tour sangat positif dan berharap dapat memotivasi siswa untuk aktif mencari pengetahuan agar berprestasi baik di sekolah

Magnetic Structure and Interactions in the Quasi-1D Antiferromagnet CaV2_2O4_4

CaV$_2$O$_4$ is a spin-1 antiferromagnet, where the magnetic vanadium ions are arranged on quasi-one-dimensional (1D) zig-zag chains with potentially frustrated antiferromagnetic exchange interactions. High temperature susceptibility and single-crystal neutron diffraction measurements are used to deduce the non-collinear magnetic structure, dominant exchange interactions and orbital configurations. The results suggest that at high temperatures CaV$_2$O$_4$ behaves as a Haldane chain, but at low temperatures, orbital ordering lifts the frustration and it becomes a spin-1 ladder.Comment: 5 pages, 4 figure

The multifrequency Siberian Radioheliograph

The 10-antenna prototype of the multifrequency Siberian radioheliograph is described. The prototype consists of four parts: antennas with broadband front-ends, analog back-ends, digital receivers and a correlator. The prototype antennas are mounted on the outermost stations of the Siberian Solar Radio Telescope (SSRT) array. A signal from each antenna is transmitted to a workroom by an analog fiber optical link, laid in an underground tunnel. After mixing, all signals are digitized and processed by digital receivers before the data are transmitted to the correlator. The digital receivers and the correlator are accessible by the LAN. The frequency range of the prototype is from 4 to 8 GHz. Currently the frequency switching observing mode is used. The prototype data include both circular polarizations at a number of frequencies given by a list. This prototype is the first stage of the multifrequency Siberian radioheliograph development. It is assumed that the radioheliograph will consist of 96 antennas and will occupy stations of the West-East-South subarray of the SSRT. The radioheliograph will be fully constructed in autumn of 2012. We plan to reach the brightness temperature sensitivity about 100 K for the snapshot image, a spatial resolution up to 13 arcseconds at 8 GHz and polarization measurement accuracy about a few percent. First results with the 10-antenna prototype are presented of observations of solar microwave bursts. The prototype abilities to estimate source size and locations at different frequencies are discussed

On the Perturbation of Synchrotron Motion in the Micro-Bunching Instability

The self-interaction of short electron bunches with their own radiation field can have a significant impact on the longitudinal beam dynamics in a storage ring. While higher bunch currents increase the power of the emitted CSR which can be provided to dedicated experiments, it simultaneously amplifies the strength of the self-interaction. Eventually, this leads to the formation of dynamically changing micro-structures within the bunch and thus fluctuating CSR emission, a phenomenon that is generally known as micro-bunching or micro-wave instability. The underlying longitudinal dynamics can be simulated by solving the VFP equation, where the CSR self-interaction can be added as a perturbation to the Hamiltonian. In this contribution, we focus on the perturbation of the synchrotron motion that is caused by introducing this additional wake field. Therefore, we adopt the perspective of a single particle and eventually comment on its implications for collective motion. We explicitly show how the shape of the parallel plates CSR wake potential breaks homogeneity in the longitudinal phase space and propose a quadrupole-like mode as potential seeding mechanism of the micro-bunching instability. Moreover, we consider synchrotron motion above the instability threshold and thereby motivate an approach to control of the occurring micro-bunching dynamics. Using dynamically adjusted RF amplitude modulations we can directly address the continuous CSR-induced perturbation at the timescale of its occurrence, which allows for substantial control over the longitudinal charge distribution. While the approach is not limited to this particular application, we demonstrate how this can significantly mitigate the micro-bunching dynamics directly above the instability threshold. The gained insights are supported and verified using the VFP solver Inovesa and put into context with measurements at KARA

Feedback Design for Control of the Micro-Bunching Instability based on Reinforcement Learning

The operation of ring-based synchrotron light sources with short electron bunches increases the emission of coherent synchrotron radiation in the THz frequency range. However, the micro-bunching instability resulting from self-interaction of the bunch with its own radiation field limits stable operation with constant intensity of CSR emission to a particular threshold current. Above this threshold, the longitudinal charge distribution and thus the emitted radiation vary rapidly and continuously. Therefore, a fast and adaptive feedback system is the appropriate approach to stabilize the dynamics and to overcome the limitations given by the instability. In this contribution, we discuss first efforts towards a longitudinal feedback design that acts on the RF system of the KIT storage ring KARA (Karlsruhe Research Accelerator) and aims for stabilization of the emitted THz radiation. Our approach is based on methods of adaptive control that were developed in the field of reinforcement learning and have seen great success in other fields of research over the past decade. We motivate this particular approach and comment on different aspects of its implementation

Excitation of Micro-Bunching in Short Electron Bunches Using RF Amplitude Modulation

In its short-bunch operation mode, the KIT storage ring KARA provides picosecond-long electron bunches, which emit coherent synchrotron radiation (CSR) up to the terahertz frequency range. Due to the high spatial compression under these conditions, the self-interaction of the bunch with its own emitted CSR induces a wake-field, which significantly influences the longitudinal charge distribution. Above a given threshold current, this leads to the formation of dynamically evolving micro-structures within the bunch and is thus called micro-bunching instability. As CSR is emitted at wavelengths corresponding to the spatial dimension of the emitter, these small structures lead to an increased emission of CSR at higher frequencies. The instability is therefore deliberately induced at KARA to provide intense THz radiation to dedicated experiments. To further increase the emitted power in the desired frequency range, we consider the potential of RF amplitude modulations to intentionally excite this form of micro-bunching in short electron bunches

Spectral and spatial observations of microwave spikes and zebra structure in the short radio burst of May 29, 2003

The unusual radio burst of May 29, 2003 connected with the M1.5 flare in AR 10368 has been analyzed. It was observed by the Solar Broadband Radio Spectrometer (SBRS/Huairou station, Beijing) in the 5.2-7.6 GHz range. It proved to be only the third case of a neat zebra structure appearing among all observations at such high frequencies. Despite the short duration of the burst (25 s), it provided a wealth of data for studying the superfine structure with millisecond resolution (5 ms). We localize the site of emission sources in the flare region, estimate plasma parameters in the generation sites, and suggest applicable mechanisms for interpretating spikes and zebra-structure generation. Positions of radio bursts were obtained by the Siberian Solar Radio Telescope (SSRT) (5.7 GHz) and Nobeyama radioheliograph (NoRH) (17 GHz). The sources in intensity gravitated to tops of short loops at 17 GHz, and to long loops at 5.7 GHz. Short pulses at 17 GHz (with a temporal resolution of 100 ms) are registered in the R-polarized source over the N-magnetic polarity (extraordinary mode). Dynamic spectra show that all the emission comprised millisecond pulses (spikes) of 5-10 ms duration in the instantaneous band of 70 to 100 MHz, forming the superfine structure of different bursts, essentially in the form of fast or slow-drift fibers and various zebra-structure stripes. Five scales of zebra structures have been singled out. As the main mechanism for generating spikes (as the initial emission) we suggest the coalescence of plasma waves with whistlers in the pulse regime of interaction between whistlers and ion-sound waves. In this case one can explain the appearance of fibers and sporadic zebra-structure stripes exhibiting the frequency splitting.Comment: 11 pages, 5 figures, in press; A&A 201

Observing the Sun with Atacama Large Millimeter/submillimeter Array (ALMA): High Resolution Interferometric Imaging

Observations of the Sun at millimeter and submillimeter wavelengths offer a unique probe into the structure, dynamics, and heating of the chromosphere; the structure of sunspots; the formation and eruption of prominences and filaments; and energetic phenomena such as jets and flares. High-resolution observations of the Sun at millimeter and submillimeter wavelengths are challenging due to the intense, extended, low- contrast, and dynamic nature of emission from the quiet Sun, and the extremely intense and variable nature of emissions associated with energetic phenomena. The Atacama Large Millimeter/submillimeter Array (ALMA) was designed with solar observations in mind. The requirements for solar observations are significantly different from observations of sidereal sources and special measures are necessary to successfully carry out this type of observations. We describe the commissioning efforts that enable the use of two frequency bands, the 3 mm band (Band 3) and the 1.25 mm band (Band 6), for continuum interferometric-imaging observations of the Sun with ALMA. Examples of high-resolution synthesized images obtained using the newly commissioned modes during the solar commissioning campaign held in December 2015 are presented. Although only 30 of the eventual 66 ALMA antennas were used for the campaign, the solar images synthesized from the ALMA commissioning data reveal new features of the solar atmosphere that demonstrate the potential power of ALMA solar observations. The ongoing expansion of ALMA and solar-commissioning efforts will continue to enable new and unique solar observing capabilities.Comment: 22 pages, 12 figures, accepted for publication in Solar Physic