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This paper presents fully automatic control of an unmanned aerial vehicle (UAV) from taxiing and takeoff to landing based on a single-antenna GPS receiver. In this paper, inertial sensors such as gyros and accelerometers are not used at all to show the full potential of a single-antenna GPS receiver based attitude determination system. DGPS is implemented to give high accuracy position information for automatic taxiing, landing and takeoff on the runway. For a fixed wing aircraft, under the assumption of coordinated flight, the attitude information called as pseudo-attitudes can be estimated from the measurements of a single-antenna GPS receiver. Therefore full state variables for the automatic control can be obtained from single-antenna GPS receiver. In addition to GPS receiver, only an airspeed sensor is added because the velocity relative to the air is very important during landing and takeoff. The forward velocity is replaced with the airspeed obtained from Pitot tube. From linearized equations of motions around the steady state, LQR controllers for takeoff and landing are built. In particular, the flare controller that controls the pitch, altitude and airspeed of a UAV is designed. During flight tests, the aircraft taxies and takes off the runway, follows the predefined waypoint path, and then lands on the runway along the curved approach path, all fully automatically. Based on flight test results, a single-antenna GPS receiver can be used as a main sensor for a backup or a low-cost control system of UAVs

The performance characteristics of the polymer electrolyte fuel cells (PEFCS) were investigated under various humidification conditions at steady-state and transient conditions. The PEFC studied in this study was characterized by I-V curves in the potentiostatic mode and EIS (electrochemical impedance spectroscopy). The I-V curves representing steady-state performance were obtained from OCV to 0.25 V, and the dynamic performance responses were obtained at some voltages. The effects of anodic external humidification were measured by varying relative humidity of hydrogen from 20% to 100% while dry air was supplied in the cathode. At the high voltage region, the performance became higher with the increase of the temperature, while at the low voltage region, the performance decreased with the increase of temperature. The EIS showed that ohmic losses were larger at the dry condition of membrane and the effects of mass transport losses increased remarkably when the external and self-humidification were high. The dynamic responses were also monitored by changing the voltage of the PEFC instantly. As the temperature increased, the current reached steady-state earlier. The self-humidification with the generated water delayed the stabilization of the current except for low voltage conditions.

Various Internet of Things (IoT) Platforms are currently announced by major IT companies. Google also announced IoT open-sourced platform project which called as Physical Web. If Physical Web is released to the IoT marketplace, a number of beacons would be in demand because each service requires at least one beacon for connectivity. Small area which set multiple beacons are set up occur interference each other. So it should be considered to identify accurately which beacon broadcasts the signals. The device based on Physical Web identifies priority of beacons through distance using Received Signal Strength Indicator (RSSI). In this paper, we prove the limit of current beacon identification for Physical Web. Also we suggest the improvement of beacon identification using low pass filter in the small area. To verify that proposed idea is applicable in real life, we model the service called ALLFIT which is built with physical web in small area. Therefore, the proposed idea is expected to be a key role in IoT service architecture.

Application of nanoparticles for controlling plant pathogens is a rapidly emerging area in plant disease management, and nanoparticles synthesis methods that are economical and ecofriendly are extensively investigated. In this project, we investigated the potential of silver nanoparticles (AgNPs) synthesized with aqueous extract of Artemisia absinthium against several Phytophthora spp., which cause many economically important crop diseases. In in vitro dose-response tests conducted in microtiter plates, 10 µg ml−1 of AgNPs inhibited mycelial growth of P. parasitica, P. infestans, P. palmivora, P. cinnamomi, P. tropicalis, P. capsici, and P. katsurae. Detailed in vitro dose-response analyses conducted with P. parasitica and P. capsici revealed that AgNPs synthesized with A. absinthium extract were highly potent (IC50: 2.1 to 8.3 µg ml−1) and efficacious (100%) in inhibiting mycelial growth, zoospore germination, germ tube elongation, and zoospore production. Interestingly, AgNP treatment accelerated encystment of zoospores. Consistent with in vitro results, in planta experiments conducted in a greenhouse revealed that AgNP treatments prevented Phytophthora infection and improved plant survival. Moreover, AgNP in in planta experiments did not produce any adverse effects on plant growth. These investigations provide a simple and economical method for controlling Phytophthora with AgNP without affecting normal plant physiology.

We propose a quality-aware media access control (MAC) protocol for real-time voice delivery in cognitive radio- (CR-) enabled wireless sensor networks (WSNs). The temporal structure of the system model is addressed by using periodic timeslots in order to make more efficient use of the spectrum. In our proposed temporal structure, a bandwidth broker in such centralized CR networks (CCRNs) is selected as a central counterpart to synchronize with secondary users (SUs) and assign spectral resources to them. We develop an analytical model for SUs for the Call Admission Control (CAC) of voice traffic using the quality of service (QoS) requirements of delay bound and delay bound violation probability. Ours is an approach that provides reliable data transmission and reduces packet delay and packet delay jitter. In addition to the aforementioned packet-level performance metrics, we calculated a call-level performance metric, that is, the number of acceptable SUs, satisfying QoS requirements.

This research explicates the construct of social ability and describes the relationship between students' academic motivation and social ability in online learning environments. Findings reveal perceived peers social presence, perceived written communication skills, perceived instructor social presence, comfort with sharing personal information, and social navigation as the five factors that define social ability. In addition, the multivariate multiple regression analyses indicate that different motivational constructs vary in their relationships with the multiple social ability factors. Intrinsic goal orientation is related to perceived peers social presence. Self-efficacy explains the variance of perceived instructor social presence and comfort with sharing personal information. Task value is associated with social navigation and both perceived peers and instructor social presence. Additional studies are needed to replicate the current findings and further explicate social ability in online learning, to continue to improve the social ability instrument, and to examine the value of other academic motivation beliefs in predicting social ability as well as that of social ability in predicting learning outcomes.

In this paper, we propose an Enhanced Message Concatenation (EMC) scheme for Quality of Service (QoS) provision in multi-hop Combat Net Radio (CNR). The key focus of this paper is the performance enhancement of the MIL-STD-188-220-based Deterministic Adaptable Priority and Network Access Delay (DAP-NAD) mechanism for QoS provision to low priority messages. To illustrate: in a battlefield, as long as a station has urgent messages to transmit, a low priority message cannot be transmitted, because a traditional DAP-NAD mechanism is specialized on urgent message transmission. However, low priority messages like Situational Awareness (SA) messages are also very important for a mission's completion. Therefore, all messages must be given equal priority. Nevertheless, a traditional DAP-NAD mechanism cannot guarantee QoS to low priority messages. So, we propose to enhance the DAP-NAD mechanism for message concatenation by using T-bits of data link. The proposed scheme is thoroughly examined by simulation method, and the results show that the proposed scheme significantly reduces the packet delay time and improves the performance of the MIL-STD-188-220-based traditional DAP-NAD mechanism.

Near-infrared (NIR) fluorescent probes are increasingly popular in biological imaging and sensing, as long-wavelength (650-900 nm) excitation and emission have the advantages of minimum photodamage, deep tissue penetration, and minimum interference from autofluorescence in living systems. Here, a series of long-wavelength BODIPY dyes SPC, DC-SPC, DPC, and DC-DPC are synthesized conveniently and efficiently. They exhibit excellent photophysical properties in far red to near-infrared region, including large extinction coefficients, high fluorescence quantum yields, good photostability, and reasonable two-photon absorption cross section. Comparison of single-molecular imaging confirms that DPC is a much more efficient and more photostable NIR fluorophore than the commonly used Cy5. Also importantly, two kinds of convenient functionalization sites have been reserved: the aryl iodide for organometallic couplings and the terminal alkyne groups for click reactions. Further derivatives DC-SPC-PPh3 exhibit specificity to localize in mitochondria. The introduction of triphenylphosphonium (TPP) moieties mediates its hydrophilic-lipophilic balance and makes DC-SPC-PPh3 appropriate for cell labeling. Their long-wavelength emission at ∼650 nm can efficiently avoid the spectral crosstalk with other probes emitting in the visible light region. Superior photostability, low cytotoxicity, and two-photon excitable properties demonstrate its utility as a standard colocalizing agent to estimate the other probes' local distribution.

Two squaraine (SQ) dyes, N-propanesulfonate-benzothiazolium squaraine (SQ-1) and N-propanesulfonate-benzoindolium squaraine (SQ-2), were synthesized with sulfonate groups to increase water solubility. Both dyes are almost nonfluorescent in aqueous solution with fluorescent quantum yields of 0.03, but exhibited fluorescence enhancement after noncovalently binding with bovine serum albumin (BSA). Upon addition of BSA, the fluorescence intensity increased by ca. a factor of 10, along with a 10-fold extension in the fluorescence lifetime. SQ-1 and SQ-2 interacted with BSA efficiently and appeared to show a preference for binding at site II, which involves combinational effects of electrostatic and hydrophobic interactions. The fluorogenic squaraine dyes were then used to label BSA, forming BSA-based nanoparticles (NPs) through noncovalent binding. The resulting BSA-SQ NPs exhibited enhanced near-IR fluorescence and reduced aggregation of the squaraine moiety. The BSA-SQ NPs were used for cell incubation and bioimaging studies. Confocal fluorescent images were obtained for HCT 116 cells incubated with the BSA-SQ NPs and LysoSensor Green, demonstrating the utility of the NP probes for intracellular imaging. This strategy ovecomes the generally low fluorescence emission of SQ dyes in water and aggregation-reduced fluorescence, providing a versatile strategy for sensing and imaging in biological environments.

Controlling the aggregation behavior of organic dyes is important for understanding and exploring supramolecular assembly utilizing the specific characteristics of aggregation. Regulating J-aggregation by electrostatic interactions between anionic polyelectrolytes and cationic dyes has gained growing interest. Here, we report the formation of J-aggregates of a water-soluble cationic squaraine dye, 4-(pyridinium-1-yl)butylbenzothiazolium squaraine (SQ), using poly(acrylic acid) sodium salt (PAA-Na) as a template. Electrostatic interactions between the PAA-Na polyelectrolyte and the cationic SQ dye enhanced J-aggregation; the absorbance of the resulting J-band with the polyelectrolyte template was much sharper than the absorbance of the J-aggregate formed using a high concentration of NaCl. Significantly, removal of the polyelectrolyte PPA-Na template by the introduction of calcium ions, which can form stronger ionic binding with carboxylate groups, dissociated J-aggregates, freeing the SQ molecules back to unaggregated or lower aggregate forms. To demonstrate the reversibility of the J-aggregate formation cycle, an in situ experiment was conducted that showed 60% reversibility of the second cycle. In addition, an enhancement by ca. 23 times per repeat unit of the two-photon absorption (2PA) cross section was observed at 920 nm for the polyelectrolyte template-SQ J-aggregate compared to unaggregated or lower aggregate SQ. These results suggest a prominent role of polyelectrolyte templated SQ J-aggregation in the enhancement of 2PA efficiency and provide a means of modulating supramolecular assembly.

Terminal area is very important airspace resource due to the limited capacity. Because several arrival traffics from different origin airport merge at arrival fix, the queue for arrival stream generally is formed at arrival fix and the inherent delay is propagated further out. Moreover it leads that arrivals do path stretching and speed adjustment to absorb that delay with consuming much more fuel than it was required. However this developed delay is often not distributed evenly, therefore some fixes experience unbearable delays while other fixes might idle. In this paper, we suggest a new approach to assign fix to resolve this issue while minimizing total consumed fuel and environmental impact in terminal airspace. The proposed model assigns arrival and departure fix for each arrival and departure respectively, considering the fix and runway capacity constraints. The proposed optimization model is beneficial to improve terminal area efficiency and local environment. In addition, this model functions more effectively at severe weather condition when existing unbalanced traffic demand.

Cognitive radio (CR) technology is envisioned to solve the scarcity and inefficient use of wireless spectrum by dynamically and opportunistically accessing the available spectrum without causing a significant interference to the primary users (PU). In this paper, we propose a solution to the problem on how cognitive radios can initially find each other under the dynamically changing available spectrum. The easiest and common practice to tackle this problem is to dedicate a control channel on which the nodes can rendezvous with each other. However, a dedicated common control channel has severe drawbacks and is not good choice for CR networks. In this paper, we propose Deterministic Approach to Rendezvous Channel Setup (DARC) scheme in which one of the free channels is chosen as a rendezvous channel by a central entity. Simulation results show that our proposed scheme has significantly lower time to rendezvous and gives better protection to the PU than previously proposed schemes.

MANET (Mobile Ad-hoc Network) has been developed for tactical networks consisting of mobile wireless nodes with various platforms. The secure delivery of mission-critical C2 (Command and Control) messages is one of critical requirements in tactical environments. However, the provision of QoS(Quality of Service) as well as the mission-critical message delivery are still ongoing problem to be solved in MANET due to its lack of resources and harsh propagation environments. In this paper, we propose a label-switched multi-path routing protocol (LMRP) to guarantee the secure delivery of mission-critical messages. To balance between the QoS support for non-mission-critical flows and the preemption for mission-critical flows, we also propose the packet forwarding scheme. The performances of the proposed method are evaluated using OPNET simulator, and the simulation results show that the proposed method can improve loss, delay and delay variation performances compared to existing MANET routing schemes such as AODV.

xes to runways, and taxi costs from runways to gates. This paper also includes details of mathematical formulations and the computation method of emissions. At the end of the paper, we provide a numerical example for planning landings and takeos at the Detroit international airport. The optimization results show that ight delays reduce as much as 44.7%, much greater than the runway sequence without runway assignment. Meanwhile, the emissions of optimal solution reduce as much as 25.4%. The proposed model for strategically planning terminal airspace operations is benecial to improve airport eciency and local environments.

For tactical networks, rapid reconfiguration and recovery of network topology is highly required. In this paper, we propose an effective tactical network architecture with WMN(Wireless Mesh Network)-based backbone. To reduce the computational and maintenance complexities of tactical networks, a hierarchical architecture is considered in the proposed architecture. The proposed architecture is called called TMB (Tactical Mesh Backbone). In addition, we develop an OPNET simulator not only to evaluate the performances, but also to develop and improve core algorithms for the TMB architecture such as routing, topology management, mobility support and so on.

What should constitute knowledge bases that we expect our future teachers to gain related to pedagogically sound technology integration? Employing the Shulman's teacher knowledge base as a theoretical lens, this study examined the complexity of pre-service teachers' technological pedagogical content knowledge (TPCK) in the context of integrating problem based learning (PBL) and information and communications technology (ICT). Ninety-seven pre-service teachers in this study engaged in a collaborative lesson design project where they applied pedagogical knowledge about PBL to design a technology integrated lesson in their subject area of teaching. Data were collected from two sources: survey and lesson design artifacts. Data analyses revealed that while participants had theoretical understandings of pedagogical knowledge about PBL, their lesson designs showed a mismatch among technology tools, content representations, and pedagogical strategies, indicating conflicts in translating pedagogical content knowledge into designing pedagogically sound, technology integrated lessons. The areas that students perceived to be particularly challenging and difficult include: a) generating authentic and ill-structured problems for a chosen content topic, b) finding and integrating ICT tools and resources relevant for the target students and learning activities, and c) designing tasks with a balance between teacher guidance and student independence. The present study suggests the potential of two explanations for such difficulties: lack of intimate connection among beliefs, knowledge, and actions, and insufficient repertoires for teaching with technology for problem based learning.

For the past decade, handheld devices with mobile and wireless capabilities have emerged as the next promising generation of technology for teaching and learning. Today, handheld devices such as mobile phones, personal digital assistants (PDAs), portable gaming devices, and tablet PCs have already become pervasive in daily lives of students. With this trend, there has been increased interest as to how mobile technologies can be used to enhance teaching and learning. One of the challenges for educators is to examine how we can use the new innovations of mobile technologies to create learning experiences that are often limited in traditional classroom environments. The purpose of this article, therefore, is to provide innovative and practical applications of mobile technologies in a variety of educational contexts, including from K-12 to higher education and informal learning.

RFID is a technology for automated identification of objects and people. But, it is possible to leak much side channel information related to secret information when the tags and a reader run on system. Especially, an attacker get physical access to the chip or its field and perform so called side channel attacks like a DPA or a DPFA which make it possible to obtain a secret key stored on the device. In this paper, we describe a modified power analysis and power frequency analysis attacks on Telos RFID device which side channel analysis is applied to ARIA algorithm with the Hamming weight of the intermediate results. Besides, we experiment the power analysis attacks on above device both the time and the frequency domain. Finally, we analyze the experimental results to find a cause that our methods are not applied to Telos module.

Angle-resolved photoemission spectroscopy (ARPES) data from the electron-doped cuprate superconductor ${\mathrm{Sm}}_{1.86}{\mathrm{Ce}}_{0.14}\mathrm{Cu}{\mathrm{O}}_{4}$ show a much stronger pseudogap or hot-spot effect than that observed in other optimally doped $n$-type cuprates. Importantly, these effects are strong enough to drive the zone-diagonal states below the chemical potential, implying that $d$-wave superconductivity in this compound would be of the nodeless gap variety. The gross features of the Fermi surface topology and low-energy electronic structure are found to be well described by reconstruction of bands by a $\sqrt{2}\ifmmode\times\else\texttimes\fi{}\sqrt{2}$ order. Comparison of the ARPES and optical data from the same sample shows that the pseudogap energy observed in optical data is consistent with the interband transition energy of the model, allowing us to have a unified picture of pseudogap effects. However, the high-energy electronic structure is found to be inconsistent with such a scenario. We show that a number of these model inconsistencies can be resolved by considering a short-range ordering or inhomogeneous state.

This paper presents automatic taxiing, takeoff and landing of a UAV based on a single-antenna GPS receiver. In this paper, inertial sensors such as gyros and accelerometers are not used at all to show the full potential of a single-antenna GPS receiver based attitude determination system. DGPS is implemented to give high accuracy position information for automatic taxiing, landing and takeoff on the runway. For a fixed wing aircraft, under the assumption of coordinated flight, the attitude information called as pseudo-attitudes can be estimated from the measurements of a single-antenna GPS receiver. So full state variables for the automatic control can be obtained from single-antenna GPS receiver. In addition to GPS receiver, only an airspeed sensor is added because the velocity relative to the air is very important during landing and takeoff. The forward velocity is replaced with the airspeed obtained from Pitot tube. From linearized equations of motions around the steady state, LQR controllers for takeoff and landing are built, m particular, the flare controller that controls the pitch, altitude and airspeed of a UAV is designed. During flight tests, the aircraft taxies and takes off the runway, follows the predefined waypoint path, and then lands on the runway along the curved approach path, all fully automatically. Based on flight test results, a single-antenna GPS receiver can be used as a main sensor for a backup or a low-cost control system of UAVs.

We studied the temperature effect on vortex-core reversals in soft magnetic nanodots by micromagnetic numerical calculations within a framework of the stochastic Landau-Lifshitz-Gilbert scheme. It was determined that vortex-core-switching events at non-zero temperatures occur stochastically, and that the threshold field strength increases with temperature for a given field frequency. The mechanism of core reversals at elevated temperatures is the same as that of vortex-antivortex-pair-mediated core reversals found at the zero temperature. The reversal criterion is also the out-of-plane component of a magnetization dip that should reach −p, which is to say, mz,dip = −p, where p is the original polarization, p = +1 (−1), for the upward (downward) core. By this criterion, the creation of a vortex-antivortex pair accompanies complete vortex-antivortex-annihilation-mediated core reversals, resulting in the maximum excess of the exchange energy density, ΔEexcri ≈ 15.4 ± 0.2 mJ/cm3. This work provides the underl...

We investigated the electronic structures of the two-dimensional layered perovskite ${\mathrm{Sr}}_{2}M{\mathrm{O}}_{4}$ ($M=4d$ Ru, $4d$ Rh, and $5d$ Ir) using optical spectroscopy and polarization-dependent O $1s$ x-ray absorption spectroscopy. While the ground states of the series of compounds are rather different, their optical conductivity spectra $\ensuremath{\sigma}(\ensuremath{\omega})$ exhibit similar interband transitions, indicative of the common electronic structures of the $4d$ and $5d$ layered oxides. The energy splittings between the two ${e}_{g}$ orbitals, i.e., ${d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$, are about $2\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, which is much larger than those in the pseudocubic and $3d$ layered perovskite oxides. The electronic properties of the ${\mathrm{Sr}}_{2}M{\mathrm{O}}_{4}$ compounds are discussed in terms of the crystal structure and the extended character of the $4d$ and $5d$ orbitals.

In this paper we critically review and analyze previous research on collaborative concept mapping in both face-to-face and networked environments. Although research has shown the positive effects of collaborative concept mapping on learning in face-to-face learning environments, there is a dearth of research which specifically focuses on the potential value of adopting collaborative concept mapping in online learning environments. Newly developed concept mapping software which operates via the Internet makes it possible for distance learners to implement concept mapping as a learning tool for co-constructing knowledge. Using our analysis of current research we provide some directions for future research in the use of concept mapping for online learning.

The charge transport in polydiacetylene quasi-1D single crystals(PDA-PTS) has been studied as a functionof temperature, electric and magnetic fields. In the Ohmic regime the temperature dependence of the resistivity,rsTd, is characteristic of hopping conduction with a crossover at T,50 K from activated rsTd=r

We developed an augmentative communication system that generates a well-formed sentence in Korean language by symbols for people with communication disorders. The system should place a minimal burden on the users. The augmentative communication aids combine the benefits of pre-stored messages with linguistic prediction capabilities to create unique acceleration techniques. Different from traditional approaches, the lexicon is organized along dimensions using a dynamic approach as a connectionist model. When the users press symbols, the software predicts verbs, which are displayed in scanning modes based on semantic markers. In order to generate the well-formed sentences, adequate postpositions follow it according to verbs for each input word.