Factorization identities for reflected processes, with applications

We derive factorization identities for a class of preemptive-resume queueing systems, with batch arrivals and catastrophes that, whenever they occur, eliminate multiple customers present in the system. These processes are quite general, as they can be used to approximate Levy processes, diffusion processes, and certain types of growth-collapse processes; thus, all of the processes mentioned above also satisfy similar factorization identities. In the Levy case, our identities simplify to both the well-known Wiener-Hopf factorization, and another interesting factorization of reflected Levy processes starting at an arbitrary initial state. We also show how the ideas can be used to derive transforms for some well-known state-dependent/inhomogeneous birth-death processes and diffusion processes

Perilaku Birokrasi Pemerintah Dalam Pelayanan Puskesmas Di Kota Makassar

Puskesmas merupakan lembaga pemerintah yang berfungsi melakukan pelayanan kesehatan dasar menuju paradigma sehat. Pelayanan kesehatan terdiri dari pelayanan kesehatan perseorangan dan pelayanan kesehatan masyarakat dengan kegiatan bersifat promotif, preventif, kuratif dan rehabilitatif. Penelitian ini bertujuan untuk: (1) menganalisis dan menjelaskan perilaku birokrasi pemerintah dalam pelayanan Puskesmas di kota Makassar, (2) menganalisis dan menjelaskan kualitas pelayanan Puskesmas di kota Makassar, dan (3) menganalisis dan menemukan faktor yang berkaitan dengan perilaku birokrasi Puskesmas di kota Makassar.Lokasi penelitian dilakukan pada Puskesmas yang sudah berstandar ISO-9001 yaitu Puskesmas Kassi-Kassi dan belum berstandar ISO-9001 yaitu Puskesmas Barombong di Kota Makassar, dengan jenis penelitian kualitatif. Sumber data diperoleh dari informan dengan teknik wawancara, observasi dan dokumentasi. Informan terdiri dari unsur birokrat puskesmas sebagai penyelenggara pelayanan dan unsur masyarakat sebagai pengguna layanan.Hasil penelitian menunjukkan bahwa: (1) perilaku birokrasi dengan prinsip rasionalitas universal belum inovatif melakukan program-program pelayanan kesehatan sehingga pelaksanaan tugas-tugas pelayanan kesehatan berlangsung apa adanya, perilaku birokrasi dengan prinsip hirarki kurang terkoordinasi baik sehingga beban tugas ganda menjadi kurang terkendali, dan perilaku birokrasi dengan prinsip diskresi kurang memperoleh kebebasan menjalankan kewenangan sesuai kebutuhan riil Puskesmas dari kebijakan yang bersifat top-down. (2) Aspek kualitas pelayanan puskesmas, tersedianya sarana dan prasarana pendukung program pelayanan kurang terjangkau, kepuasan masyarakat dari kualitas yang diterimanya ditentukan oleh kondisi masyarakat setempat. (3) Faktor-faktor yang berkaitan dengan penerapan perilaku birokrasi puskesmas yang dapat berlangsung efisien mendukung proses penyelenggaraan pelayanan melalui kepemimpinan transformasional, birokrasi profesional dan kewenangan khusus

Queues with random back-offs

We consider a broad class of queueing models with random state-dependent vacation periods, which arise in the analysis of queue-based back-off algorithms in wireless random-access networks. In contrast to conventional models, the vacation periods may be initiated after each service completion, and can be randomly terminated with certain probabilities that depend on the queue length. We examine the scaled queue length and delay in a heavy-traffic regime, and demonstrate a sharp trichotomy, depending on how the activation rate and vacation probability behave as function of the queue length. In particular, the effect of the vacation periods may either (i) completely vanish in heavy-traffic conditions, (ii) contribute an additional term to the queue lengths and delays of similar magnitude, or even (iii) give rise to an order-of-magnitude increase. The heavy-traffic asymptotics are obtained by combining stochastic lower and upper bounds with exact results for some specific cases. The heavy-traffic trichotomy provides valuable insight in the impact of the back-off algorithms on the delay performance in wireless random-access networks

Slow slip in subduction zones: Reconciling deformation fabrics with instrumental observations and laboratory results

Cataclasites are a characteristic rock type found in drill cores from active faults as well as in exposed fossil subduction faults. Here, cataclasites are commonly associated with evidence for pervasive pressure solution and abundant hydro­ fracturing. They host the principal slip of regular earthquakes and the family of so­called slow earthquakes (episodic slip and tremor, low to very low frequency earthquakes, etc.). Slip velocities associated with the formation of the different types of cataclasites and conditions controlling slip are poorly constrained both from direct observations in nature as well as from experimental research. In this study, we explore exposed sections of subduction faults and their dominant microstructures. We use recently proposed constitutive laws to estimate deformation rates, and we compare predicted rates with instrumental observations from subduction zones. By identifying the maximum strain rates using fault scaling relations to constrain the fault core thickness, we find that the instrumental shear strain rates identified for the family of “slow earthquakes” features range from 10−3s−1 to 10−5s−1. These values agree with estimated rates for stress corrosion creep or brittle creep possibly controlling cataclastic deformation rates near the failure threshold. Typically, pore­fluid pressures are suggested to be high in subduction zones triggering brittle deformation and fault slip. However, seismic slip events causing local dilatancy may reduce fluid pressures promoting pressure­solution creep (yielding rates of <10−8 to 10−12s−1) during the interseismic period in agreement with dominant fabrics in plate interface zones. Our observations suggest that cataclasis is controlled by stress corrosion creep and driven by fluid pressure fluctuations at near­lithostatic effective pressure and shear stresses close to failure. We posit that cataclastic flow is the dominant physical mechanism governing transient creep episodes such as slow slip events (SSEs), accelerating preparatory slip before seismic events, and early afterslip in the seismogenic zone

Tuberculosis Patient-Centred Care

Increasing complexity of tuberculosis (TB) is one of the causes that TB is still the leading cause of death by an infectious disease. Among the complicating factors are increasing drug resistance and comorbidities. Patient-centred care, and even more individualised treatment, would be the way forward. The different aspects of patient-centred care model, including medical, social and supportive care are discussed.</p

Evaluation of data loggers for measuring lying behavior in dairy calves

Lying behavior might indicate how the animal interacts with its environment and is an important indicator of cow and calf comfort. Measuring behavior can be time consuming; therefore, behavioral recording with the help of loggers has become common. Recently, the Hobo Pendant G data logger (Onset Computer Corp., Bourne, MA) was validated for measuring lying behavior in cows but no work to date has validated this logger for measuring lying behavior in calves. The objective of this study was to test the accuracy of the Hobo Pendant G data logger for measuring total lying time and frequency of lying bouts in dairy calves. In 2 experiments (experiment 1: thirty-seven 2-h observation periods; experiment 2: nineteen 24-h observation periods), we tested the effect of 2 different recording intervals, the effect of attachment to different legs, and the effect of removing short, potentially erroneous readings. We found an excellent relationship when comparing the 30-s and 60-s recording intervals. For total lying time and bout frequency, the highest correlation was found when the logger was attached to the hind legs and recording was conducted with a 60-s sampling interval. In experiment 2, average total lying time was 1,077 ± 54 min/24 h (18.0 ± 0.9h/24h), with an average frequency of 19.4 ± 4.5 bouts per day. Predictability, sensitivity, and specificity for experiment 2 were >97% using the 60-s recording interval and removing single readings of lying or standing from the data set compared with direct observation as reference. The data logger accurately measured total lying time and bout frequency when the sampling interval was ≤ 60 s and short readings of lying and standing up to 1 min were converted into the preceding behavior. The best results were achieved by attaching the logger to the right hind leg