POTENTIAL OF STATIC, KINEMATIC, AND RTK IN OPEN SKY USING GPS ONLY AND GPS + GLONASS SIGNALS

ABSTRACT: It is now simple to use Global Navigation Satellite System (GNSS) anyplace due to the rapid developments and variety of GNSS satellite techniques. Several satellite systems, including GPS, GLONASS, BIUDO, and GALILEO, are widely available and used. The Differential Global Navigation Satellite System (DGNSS) is being utilized for many different applications, particularly those involving surveying and mapping. For establishing control points (Cps) in the open sky with moderate accuracy, it may be helpful to compare the usage of post-processing methods including static and kinematic also real-time kinematic (RTK) for position accuracy to differentiate their accuracies. The comparison depends on using the constellation of GPS only and GPS + GLONASS. For this purpose, fieldwork employing the three approaches with the two constellations (GPS and GLONASS) was done on five test points. The selected points were in the open sky, and the raw data was collected on tripods in the three methods. Leica 8.4 Geo Office software was used for the raw data processing after the five Cps were observed using a Leica Viva GS15 dual frequency receiver which supports GPS and GLONASS signals. The 3D position accuracy of the Cps was obtained by the three approaches using signals from GPS + GLONASS and GPS only. The advantages and disadvantages of using each approach were discusse

Cooperative performance measurement proposal (a test with the cooperfic© tool for wine cooperatives in Languedoc-Roussillon)

Purpose: French wine cooperatives show differences of corporate objectives, but also common ones with private wine merchants, as they face a common economic environment. The traditional controlling and financial models do not seem adequate to measure ‘sustainable social economy’ performances advocated by the cooperatives’ philosophy. The main difficulty is that their specific corporate governance introduces competition between short term maximum payments to their grape suppliers-patrons and long term investment potentials. How, therefore, facing this “cooperative dilemma”, should they balance these conflicting objectives, and which performance measurement specificities should wine cooperatives adopt? Design/methodology: In order to try and answer this question, the design of an adapted data base appears to be necessary. It should take into account the apparent antinomy of the cooperatives’ short term and long term objectives, in the context of an economically sustainable development. An original economic and financial measurement model is proposed, and we test it with COOPERFIC?, a decision-aid tool for wine cooperatives, based upon a specially constructed data base in Languedoc-Roussillon. Findings: The exploratory results obtained from the test of an original performance measurement model on an ad hoc sample of wine cooperatives lead to new insights into cooperative performance and to some useful guidelines in terms of cooperative governance. Results show how the conflict between their short term and long term performances could be balanced, in order for this specific type of firm to reach its economic and social objectives Practical implications: A conjoint short and long term economic indicators approach illustrates the necessary balance in the cooperative governance, and constitutes a performance measurement model answering some of these wine cooperatives’ Board and management questions ...French Abstract : Propos: Les caves coopératives françaises font apparaître des points de divergence, mais aussi de convergence avec les négociants en vin, en matière d’objectifs d’entreprise, dans la mesure où elles font face au même environnement économique. Toutefois, les modèles traditionnels financiers et de contrôle de gestion ne semblent pas adaptés à la mesure des performances d’une économie sociale durable, dont les valeurs sont portées par la philosophie coopérative. La principale difficulté réside dans le fait que leur mode de gouvernance spécifique entraîne un conflit permanent entre la rémunération maximale à court terme des vignerons coopérateurs et les capacités d’investissement à long terme. Aussi, face à ce « dilemme coopératif », comment les entreprises coopératives viticoles doivent-elles concilier ces objectifs conflictuels et quels types de mesures de performance spécifiques devraient-elles adopter ? Design/méthodologie: Afin d’arriver à répondre à cette double question, la conception d’une base de données spécifique apparaît nécessaire. Elle se doit de prendre en compte l’apparente antinomie des objectifs à court terme et à long terme des coopératives, dans le cadre d’un développement économique durable. Un modèle de mesure de performance économique et financière est ici proposé et testé à l’aide de l’outil d’aide à la décision COOPERFIC?, spécifique aux caves coopératives du Languedoc-Roussillon. Résultats: Les résultats exploratoires provenant du test d’un modèle original de mesure de la performance sur un échantillon ad hoc de caves coopératives conduit à de nouvelles perspectives en matière de performance coopérative, ainsi qu’à des conseils utiles ayant trait à la gouvernance. Ces résultats montrent la façon dont le conflit entre performances à court terme et à long terme pourrait être maîtrisé en vue d’atteindre les objectifs économiques et sociaux de ce type particulier d’entreprise. Implications managériales: Une approche conjointe des indicateurs économiques à court et long terme illustre le nécessaire équilibre à trouver en matière de gouvernance coopérative et constitue un modèle de mesure de la performance répondant à un certain nombre de questions relatives au conseil d’administration et au management général des coopératives.WINE COOPERATIVES; GOVERNANCE; PERFORMANCE MEASUREMENT; INDICATORS; LANGUEDOC ROUSSILLON; FRANCE

POTENTIAL OF STATIC, KINEMATIC, AND RTK IN OPEN SKY USING GPS ONLY AND GPS + GLONASS SIGNALS

ABSTRACT: It is now simple to use Global Navigation Satellite System (GNSS) anyplace due to the rapid developments and variety of GNSS satellite techniques. Several satellite systems, including GPS, GLONASS, BIUDO, and GALILEO, are widely available and used. The Differential Global Navigation Satellite System (DGNSS) is being utilized for many different applications, particularly those involving surveying and mapping. For establishing control points (Cps) in the open sky with moderate accuracy, it may be helpful to compare the usage of post-processing methods including static and kinematic also real-time kinematic (RTK) for position accuracy to differentiate their accuracies. The comparison depends on using the constellation of GPS only and GPS + GLONASS. For this purpose, fieldwork employing the three approaches with the two constellations (GPS and GLONASS) was done on five test points. The selected points were in the open sky, and the raw data was collected on tripods in the three methods. Leica 8.4 Geo Office software was used for the raw data processing after the five Cps were observed using a Leica Viva GS15 dual frequency receiver which supports GPS and GLONASS signals. The 3D position accuracy of the Cps was obtained by the three approaches using signals from GPS + GLONASS and GPS only. The advantages and disadvantages of using each approach were discusse

Asymptotics of Transmit Antenna Selection: Impact of Multiple Receive Antennas

Consider a fading Gaussian MIMO channel with $N_\mathrm{t}$ transmit and $N_\mathrm{r}$ receive antennas. The transmitter selects $L_\mathrm{t}$ antennas corresponding to the strongest channels. For this setup, we study the distribution of the input-output mutual information when $N_\mathrm{t}$ grows large. We show that, for any $N_\mathrm{r}$ and $L_\mathrm{t}$, the distribution of the input-output mutual information is accurately approximated by a Gaussian distribution whose mean grows large and whose variance converges to zero. Our analysis depicts that, in the large limit, the gap between the expectation of the mutual information and its corresponding upper bound, derived by applying Jensen's inequality, converges to a constant which only depends on $N_\mathrm{r}$ and $L_\mathrm{t}$. The result extends the scope of channel hardening to the general case of antenna selection with multiple receive and selected transmit antennas. Although the analyses are given for the large-system limit, our numerical investigations indicate the robustness of the approximated distribution even when the number of antennas is not large.Comment: 6 pages, 4 figures, ICC 201

The effect of test characteristics on aberrant response patterns in computer adaptive testing.

The advantages that computer adaptive testing offers over linear tests have been well documented. The Computer Adaptive Test (CAT) design is more efficient than the Linear test design as fewer items are needed to estimate an examinee\u27s proficiency to a desired level of precision. In the ideal situation, a CAT will result in examinees answering different number of items according to the stopping rule employed. Unfortunately, the realities of testing conditions have necessitated the imposition of time and minimum test length limits on CATs. Such constraints might place a burden on the CAT test taker resulting in aberrant response behaviors by some examinees. Occurrence of such response patterns results in inaccurate estimation of examinee proficiency levels. This study examined the effects of test lengths, time limits and the interaction of these factors with the examinee proficiency levels on the occurrence of aberrant response patterns. The focus of the study was on the aberrant behaviors caused by rushed guessing due to restrictive time limits. Four different testing scenarios were examined; fixed length performance tests with and without content constraints, fixed length mastery tests and variable length mastery tests without content constraints. For each of these testing scenarios, the effect of two test lengths, five different timing conditions and the interaction between these factors with three ability levels on ability estimation were examined. For fixed and variable length mastery tests, decision accuracy was also looked at in addition to the estimation accuracy. Several indices were used to evaluate the estimation and decision accuracy for different testing conditions. The results showed that changing time limits had a significant impact on the occurrence of aberrant response patterns conditional on ability. Increasing test length had negligible if not negative effect on ability estimation when rushed guessing occured. In case of performance testing high ability examinees while in classification testing middle ability examinees suffered the most. The decision accuracy was considerably affected in case of variable length classification tests

Rapid soft X-ray fluctuations in solar flares observed with the X-ray polychromator

Three flares observed by the Soft X-Ray Polychromator on the Solar Maximum Mission were studied. Flare light curves from the Flat Crystal Spectrometer and Bent Crystal Spectrometer were examined for rapid signal variations. Each flare was characterized by an initial fast (less than 1 min) burst, observed by the Hard X-Ray Burst Spectrometer (HXRBS), followed by softer gradual X-ray emission lasting several minutes. From an autocorrelation function analysis, evidence was found for quasi-periodic fluctuations with rise and decay times of 10 s in the Ca XIX and Fe XXV light curves. These variations were of small amplitude (less than 20%), often coincided with hard X-ray emissions, and were prominent during the onset of the gradual phase after the initial hard X-ray burst. It is speculated that these fluctuations were caused by repeated energy injections in a coronal loop that had already been heated and filled with dense plasma associated with the initial hard X-ray burst

On Robustness of Massive MIMO Systems Against Passive Eavesdropping under Antenna Selection

In massive MIMO wiretap settings, the base station can significantly suppress eavesdroppers by narrow beamforming toward legitimate terminals. Numerical investigations show that by this approach, secrecy is obtained at no significant cost. We call this property of massive MIMO systems `secrecy for free' and show that it not only holds when all the transmit antennas at the base station are employed, but also when only a single antenna is set active. Using linear precoding, the information leakage to the eavesdroppers can be sufficiently diminished, when the total number of available transmit antennas at the base station grows large, even when only a fixed number of them are selected. This result indicates that passive eavesdropping has no significant impact on massive MIMO systems, regardless of the number of active transmit antennas.Comment: 7 pages, 2 figures; To be presented in IEEE Global Communications Conference (Globecom) 2018 in Abu Dhabi, UA