173,051 research outputs found

    The time-of-propagation counter for Belle II

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    The Belle II detector operating at the future upgrade to the KEKB accelerator will perform high-statistics precision investigations into the flavor sector of the Standard Model. As charged hadron identification is a vital element of the experiment's success, the time-of-propagation (TOP) counter has been chosen as the primary particle identification device in the barrel region of Belle II. The TOP counter is a compact variant of the detection of internally reflected Cherenkov light (DIRC) technique and relies heavily on exquisite single photon timing resolution with micro-channel plate photomultiplier tubes. We discuss the general principles of TOP operation and optimization of the Belle II TOP configuration, which is expected to provide 4 sigma or better separation of kaons and pions up to momenta of approximately 4 GeV/c.Comment: 5 pages, 5 figures, 2 tables; Submitted to special edition of NIMA, Proceedings of RICH201

    Offline Handwritten Signature Verification - Literature Review

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    The area of Handwritten Signature Verification has been broadly researched in the last decades, but remains an open research problem. The objective of signature verification systems is to discriminate if a given signature is genuine (produced by the claimed individual), or a forgery (produced by an impostor). This has demonstrated to be a challenging task, in particular in the offline (static) scenario, that uses images of scanned signatures, where the dynamic information about the signing process is not available. Many advancements have been proposed in the literature in the last 5-10 years, most notably the application of Deep Learning methods to learn feature representations from signature images. In this paper, we present how the problem has been handled in the past few decades, analyze the recent advancements in the field, and the potential directions for future research.Comment: Accepted to the International Conference on Image Processing Theory, Tools and Applications (IPTA 2017

    A vision system planner for increasing the autonomy of the Extravehicular Activity Helper/Retriever

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    The Extravehicular Activity Retriever (EVAR) is a robotic device currently being developed by the Automation and Robotics Division at the NASA Johnson Space Center to support activities in the neighborhood of the Space Shuttle or Space Station Freedom. As the name implies, the Retriever's primary function will be to provide the capability to retrieve tools and equipment or other objects which have become detached from the spacecraft, but it will also be able to rescue a crew member who may have become inadvertently de-tethered. Later goals will include cooperative operations between a crew member and the Retriever such as fetching a tool that is required for servicing or maintenance operations. This paper documents a preliminary design for a Vision System Planner (VSP) for the EVAR that is capable of achieving visual objectives provided to it by a high level task planner. Typical commands which the task planner might issue to the VSP relate to object recognition, object location determination, and obstacle detection. Upon receiving a command from the task planner, the VSP then plans a sequence of actions to achieve the specified objective using a model-based reasoning approach. This sequence may involve choosing an appropriate sensor, selecting an algorithm to process the data, reorienting the sensor, adjusting the effective resolution of the image using lens zooming capability, and/or requesting the task planner to reposition the EVAR to obtain a different view of the object. An initial version of the Vision System Planner which realizes the above capabilities using simulated images has been implemented and tested. The remaining sections describe the architecture and capabilities of the VSP and its relationship to the high level task planner. In addition, typical plans that are generated to achieve visual goals for various scenarios are discussed. Specific topics to be addressed will include object search strategies, repositioning of the EVAR to improve the quality of information obtained from the sensors, and complementary usage of the sensors and redundant capabilities

    A preliminary training guide for utilizing high-altitude, color-infrared photography in compiling soil maps

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    Instruction for acquiring and analytically processing small-scale color-infrared photography to perform a soil resources inventory over forests of the southern U.S. is provided. Planning the project; acquiring aerial photography, materials, equipment and supplemental data; and preparing the photography for analysis are discussed. The procedures for preparing ancillary and primary component overlays are discussed. The use of correlation charts and dichotomous keys for mountain landforms, water regime, and vegetation is explained

    Penilaian kualiti persekitaran dalaman (IEQ) bangunan Akademik Institusi Pengajian Tinggi Awam (IPTA) Malaysia dalam konteks pengurusan fasiliti

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    Kualiti Persekitaran Dalaman atau Indoor Environmental Quality (IEQ) merupakan komponen penting dalam konteks bangunan mesra alam yang akan menentukan tahap kualiti penghuni di dalam sesebuah bangunan. Secara purata dianggarkan 80% kehidupan seharian manusia adalah berada di dalam bangunan. Ketidakseimbangan IEQ menyumbang kepada Sindrom Bangunan Sakit (Sick Building Syndrome) sekali gus memberi kesan kepada produktiviti para penghuni juga kepada struktur bangunan. Sehubungan itu, kajian ini dilaksanakan untuk mengenal pasti tahap kesedaran pihak pengurusan harta dan fasiliti di Institusi Pengajian Tinggi Awam (IPTA) terhadap IEQ dalam konteks bangunan akademik. Kajian ini juga bertujuan untuk mengukur tahap IEQ dan tahap kepuasan pengguna dalam bangunan akademik di IPTA. Kajian ini melibatkan bangunan akademik di 20 IPTA di Malaysia. Metodologi kajian ini menggunakan pendekatan kualitatif, kajian saintifik dan juga pendekatan secara kuantitatif. Pendekatan Kualitatif digunakan bagi menilai tahap kesedaran pihak pengurusan harta dan fasiliti IPTA melalui proses temubual yang melibatkan 20 orang responden. Manakala pendekatan kedua adalah melalui kajian saintifik ke atas bangunan akademik yang memfokuskan kepada pengukuran elemen keselesaan terma, keselesaan bunyi, kualiti udara dalaman dan pencahayaan. Hasil pengukuran elemen tersebut dibandingkan dengan piawaian dari Malaysia Standard (MS 1525;2007) dan UNESCO. Bagi setiap IPTA, lima buah bilik kuliah dijadikan sampel dengan tiga kali bacaan setiap hari selama dua hari diperolehi bagi mendapatkan bacaan purata. Seterusnya, melalui pendekatan kuantitatif, data yang diperolehi melalui kaji selidik melibatkan 500 responden dan dianalisis menggunakan perisian Statistical Package for Social Science (SPSS). Hasil kajian menunjukkan kesedaran para pengurus harta dan fasililti di IPTA terhadap IEQ adalah baik tetapi masih ada beberapa kelemahan yang perlu ditambahbaik. Hasil ujian saintifik yang diperolehi menunjukkan bacaan bagi suhu dalaman, hanya UniSZA, UTHM dan UniMAS yang menepati piawaian, manakala bagi pencahayaan, UM, UIAM, UPSI, USM, UniSZA, UTM, UTHM, UTeM, UMS dan UniMAS berada di bawah tahap piawaian ditetapkan. Bagi keamatan bunyi, hanya UM, UPM, UPSI, USM dan UniMAP yang menunjukkan bacaan pada piawaian ditetapkan. Keseluruhannya menunjukkan bacaan berada pada tahap yang sederhana dan masih lagi memerlukan pernambahbaikan. Kajian ini turut mempamerkan bacaan purata bagi setiap elemen IEQ bagi bangunan akademik seluruh IPTA. Penemuan hasil kajian ini dijangka dapat membantu pihak pengurusan harta dan fasiliti IPTA dalam usaha menambahbaik tahap IEQ dalam bangunan akademik di kampus universiti sekaligus dapat meningkatkan tahap pengurusan fasiliti dalam mencapai tahap kelestarian kampus IPTA di Malaysia

    Visualizing Magnitude and Direction in Flow Fields

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    In weather visualizations, it is common to see vector data represented by glyphs placed on grids. The glyphs either do not encode magnitude in readable steps, or have designs that interfere with the data. The grids form strong but irrelevant patterns. Directional, quantitative glyphs bent along streamlines are more effective for visualizing flow patterns. With the goal of improving the perception of flow patterns in weather forecasts, we designed and evaluated two variations on a glyph commonly used to encode wind speed and direction in weather visualizations. We tested the ability of subjects to determine wind direction and speed: the results show the new designs are superior to the traditional. In a second study we designed and evaluated new methods for representing modeled wave data using similar streamline-based designs. We asked subjects to rate the marine weather visualizations: the results revealed a preference for some of the new designs

    Kecelaruan personaliti antisosial di kalangan pelajar politeknik : satu kajian awal

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    Kajian ini adalah bertujuan untuk mengenalpasti kecelaruan personalis antisosial (KPA) yang berlaku di kalangan remaja atau muda-mudi terutama di Politeknik Malaysia yang mungkin mengakibatkan berlakunya masalah sosial di kalangan mereka. Kajian ini berbentuk kuantitatif. Sampel kajian telah dipilih di empat buah politeknik. Politeknik yang terlibat adalah politeknik zon selatan. Responden kajian ini terdiri daripada 340 orang pelajar pengambilan bam semester satu yang memasuki institusi berkenaan. Responden juga terdiri daripada pelajar peringkat sijil dan diploma daripada pelbagai pengkhususan. Instrumen yang digunakan adalah borang soal selidik. Data yang telah dikumpulkan dianalisis menggunakan Statistical Package for Social Science (SPSS). Statistik yang digunakan adalah statistik deskriptif. Dapatan kajian menunjukkan di antara 10 jenis kecelaruan, kecelaruan avoidant mencatatkan skor min tertinggi iaitu dengan skor min 3.24 (a = 1.055). Selain itu, pengkaji mendapati personaliti antisosial yang berlaku di kalangan pelajar politeknik adalah pada tahap yang sederhana iaitu skor min 2.35 (a =0.933). Hasil daripada kajian juga mendapati faktor sosial mencatatkan skor min tertinggi iaitu 2.07 (a = 0.851). Faktor keluarga pula hanya mencatatkan skor min 2.03 (g = 0.887). Pengkaji juga mendapati responden lebih gemar kepada konsep keagamaan berbanding konsep-konsep yang lain sekiranya mereka menghadapi masalah. Oleh itu diharapkan kajian ini dapat memberikan penjelasan sedikit sebanyak mengenai kecelaruan personaliti antisosial yang berlaku di kalangan pelajar politeknik di masa kini

    Pembangunan kerangka transferable skills bagi perlaksanaan penyelidikan dalam kalangan pelajar pascasiswazah di Malaysia

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    Malaysia berhasrat menjadi negara maju dan berpendapatan tinggi maka keperluan sumber manusia profesional iaitu graduan pascasiswazah adalah semakin mendesak. Namun demikian, timbul isu tentang tekanan yang dihadapi pelajar dalam menjalankan penyelidikan, seperti putus asa, hilang minat, hilang keyakinan diri, tidak fokus, mengalami tekanan mental, ketandusan idea, tidak mencapai target yang diinginkan, hilang komitmen dan gagal dalam menamatkan pengajian. Terdapat keperluan terhadap peranan transferable skills untuk melakukan pelbagai aktiviti, untuk mencapai sasaran dan menyelesaikan masalah yang timbul sepanjang proses penyelidikan. Oleh itu, kajian ini dilaksanakan untuk membangunkan kerangka transferable skills bagi perlaksanaan penyelidikan dalam kalangan pelajar pascasiswazah di Malaysia. Dalam kajian ini, pengkaji menggunakan reka bentuk penerokaan bercampur berurutan yang melibatkan kajian kualitatif dan kajian kuantitatif. Peserta temu bual iaitu seramai 11 orang pakar dan peserta kajian Fuzzy Delphi iaitu 13 orang pakar, yang telah dipilih menggunakan kaedah persampelan bertujuan. Sampel bagi kajian tinjauan pula iaitu seramai 483 pelajar pascasiswazah dalam bidang sains sosial dan kemanusiaan di universiti awam yang terdapat di Malaysia, telah dipilih menggunakan kaedah pensampelan rawak berlapis mengikut kadar. Dapatan kajian ini menunjukkan bahawa terdapat enam domain transferable skills dan 22 elemen transferable skills. Kajian ini mendapati bahawa pelajar Sarjana dan Doktor Falsafah memberikan tahap persetujuan yang tinggi terhadap enam domain dan 22 elemen transferable skills. Hasil dapatan kajian ini menunjukkan bahawa tidak terdapat perbezaan kesesuaian domain dan elemen transferable skills untuk menjalankan proses penyelidikan berdasarkan pelajar Sarjana dan Doktor Falsafah (PhD). Kajian ini juga mendapati bahawa kerangka transferable skills yang dibangunkan adalah sah dan boleh dipercayai untuk menjadi panduan bagi perlaksanaan penyelidikan dalam kalangan pelajar pascasiswazah di Malaysia. Oleh yang demikian, pengkaji berharap kerangka transferable skills yang dibangunkan melalui kajian ini dapat menjadi panduan bagi pelajar pascasiswazah untuk mencapai target yang diinginkan dan dapat menyelesaikan penyelidikan sebagaimana tempoh yang ditetapkan sehingga berjaya menamatkan pengajian

    The Potential-Density Phase Shift Method for Determining the Corotation Radii in Spiral and Barred Galaxies

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    We have developed a new method for determining the corotation radii of density waves in disk galaxies, which makes use of the radial distribution of an azimuthal phase shift between the potential and density wave patterns. The approach originated from improved theoretical understandings of the relation between the morphology and kinematics of galaxies, and on the dynamical interaction between density waves and the basic-state disk stars which results in the secular evolution of disk galaxies. In this paper, we present the rationales behind the method, and the first application of it to several representative barred and grand-design spiral galaxies, using near-infrared images to trace the mass distributions, as well as to calculate the potential distributions used in the phase shift calculations. We compare our results with those from other existing methods for locating the corotations, and show that the new method both confirms the previously-established trends of bar-length dependence on galaxy morphological types, as well as provides new insights into the possible extent of bars in disk galaxies. Application of the method to a larger sample and the preliminary analysis of which show that the phase shift method is likely to be a generally-applicable, accurate, and essentially model-independent method for determining the pattern speeds and corotation radii of single or nested density wave patterns in galaxies. Other implications of this work are: most of the nearby bright disk galaxies appear to possess quasi-stationary spiral modes; that these density wave modes and the associated basic state of the galactic disk slowly transform over time; and that self-consistent N-particle systems contain physics not revealed by the passive orbit analysis approaches.Comment: 48 pages, 16 figures. Accepted for publication in the Astronomical Journa
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