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Missouri University of Science and Technology

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2004

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Articles 61 - 87 of 87

Full-Text Articles in Physical Sciences and Mathematics

Degree Of Scaffolding: Learning Objective Metadata: A Prototype Leaning System Design For Integrating Gis Into A Civil Engineering Curriculum, Richard H. Hall, Ronaldo Luna, Michael Gene Hilgers, Aaron Joseph Taylor, John Mckenna Sullivan, Matt Buechler Jan 2004

Degree Of Scaffolding: Learning Objective Metadata: A Prototype Leaning System Design For Integrating Gis Into A Civil Engineering Curriculum, Richard H. Hall, Ronaldo Luna, Michael Gene Hilgers, Aaron Joseph Taylor, John Mckenna Sullivan, Matt Buechler

Business and Information Technology Faculty Research & Creative Works

Digital media and networking offer great potential as tools for enhancing classroom learning environments, both local and distant. One concept and related technological tool that can facilitate the effective application and distribution of digital educational resources is learning objects in combination with the SCORM (sharable content objects reference model) compliance framework. Progressive scaffolding is a learning design approach for educational systems that provides flexible guidance to students. We are in the process of utilizing this approach within a SCORM framework in the form of a multi-level instructional design. The associated metadata required by SCORM will describe the degree of scaffolding. …


A Generic Oo Architecture Language For Semantics Analysis Of Oo Specification, Xiaoqing Frank Liu Jan 2004

A Generic Oo Architecture Language For Semantics Analysis Of Oo Specification, Xiaoqing Frank Liu

Computer Science Faculty Research & Creative Works

Formal specification enables a rigorous analysis and model checking for ensuring the correctness of specification. Formal OO specification methods are of mathematical nature and the semantics of specification is purposely defined such that it is not related to the semantics of code. We propose a new language, which will lay a common semantics ground for both specification and code.


Biologically Important Thiols In Various Vegetables And Fruits, Omca Demirkol, Craig D. Adams, Nuran Ercal Jan 2004

Biologically Important Thiols In Various Vegetables And Fruits, Omca Demirkol, Craig D. Adams, Nuran Ercal

Chemistry Faculty Research & Creative Works

Biological thiols are important antioxidants, and recent studies showed that their contents vary depending on the groups of foodstuffs. Therefore, we investigated the levels of some biological thiols in various vegetables and fruits by using a sensitive high-performance liquid chromatography (HPLC) technique. Biological thiols measured in some vegetables and fruits include glutathione (L-glutamyl-L-cysteinly glycine, GSH), N-acetylcysteine (NAC), captopril [CAP (C9H15NO3S)], homocysteine (HCYS), cysteine (CYS), and -glutamyl cysteine (GGC). Our results show that biological thiol contents are between 3-349 nM/g wet weight in vegetables and 4-136 nM/g wet weight in fruits. CAP is only found in asparagus (28 nM/g wet weight). …


A Change Impact Dependency Measure For Predicting The Maintainability Of Source Code, Xiaoqing Frank Liu Jan 2004

A Change Impact Dependency Measure For Predicting The Maintainability Of Source Code, Xiaoqing Frank Liu

Computer Science Faculty Research & Creative Works

We first articulate the theoretic difficulties with the existing metrics designed for predicting software maintainability. To overcome the difficulties, we propose to measure a purely internal and objective attribute of code, namely change impact dependency, and show how it can be modeled to predict real change impact. The proposed base measure can be further elaborated for evaluating software maintainability.


Interactive Dna Sequence And Structure Design For Dna Nanoapplications, Mingjun Zhang, Chaman Sabharwal, Weimin Tao, Tzyh-Jong Tarn, Ning Xi, Guangyong Li Jan 2004

Interactive Dna Sequence And Structure Design For Dna Nanoapplications, Mingjun Zhang, Chaman Sabharwal, Weimin Tao, Tzyh-Jong Tarn, Ning Xi, Guangyong Li

Computer Science Faculty Research & Creative Works

DNA sequence and structure design is very important for DNA nanoapplications. A computer-aided design tool is needed for exploring DNA sequence and structure of interests before experimental synthesis, which is a time- and labor-consuming process. In this paper, an interactive DNA sequence and structure design software tool called DNA shop is proposed and implemented. The visualization tool can generate DNA structures by specifying, selecting, and moving DNA sequences around and display corresponding structures. Using the tool, DNA sequence and structure can be visually inspected in three-dimensional space before experimental studies.


A Scalable Approach For Reliable Downstream Data Delivery In Wireless Sensor Networks, Seung Jong Park, Ramanuja Vedantham, Raghupathy Sivakumar, Ian F. Akyildiz Jan 2004

A Scalable Approach For Reliable Downstream Data Delivery In Wireless Sensor Networks, Seung Jong Park, Ramanuja Vedantham, Raghupathy Sivakumar, Ian F. Akyildiz

Computer Science Faculty Research & Creative Works

There exist several applications of sensor networks where reliability of data delivery can be critical. While the redundancy inherent in a sensor network might increase the degree of reliability, it by no means can provide any guaranteed reliability semantics. In this paper, we consider the problem of reliable sink-to-sensors data delivery. We first identify several fundamental challenges that need to be addressed and are unique to a wireless sensor network environment. We then propose a scalable framework for reliable down-stream data delivery that is specifically designed to both address and leverage the characteristics of a wireless sensor network, while achieving …


Ultraviolet Photonic Crystal Laser, Alexey Yamilov, Hui Cao, Robert P. H. Chang, Xiaohua Wu, Xang Liu, Shuyou Li, Vinayak P. Dravid Jan 2004

Ultraviolet Photonic Crystal Laser, Alexey Yamilov, Hui Cao, Robert P. H. Chang, Xiaohua Wu, Xang Liu, Shuyou Li, Vinayak P. Dravid

Physics Faculty Research & Creative Works

We fabricated two-dimensional photonic crystal structures in zinc oxide films with focused-ion-beam etching. Lasing is realized in the near-ultraviolet frequency at room temperature under optical pumping. From the measurement of lasing frequency and spatial profile of the lasing modes, as well as the photonic band structure calculation, we conclude that lasing occurs in the strongly localized defect modes near the edges of photonic band gap. These defect modes originate from the structure disorder unintentionally introduced during the fabrication process. ©2004 American Institute of Physics


Adaptive Critic Neural Network-Based Object Grasping Control Using A Three-Finger Gripper, Gustavo Galan, Jagannathan Sarangapani Jan 2004

Adaptive Critic Neural Network-Based Object Grasping Control Using A Three-Finger Gripper, Gustavo Galan, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Grasping of objects has been a challenging task for robots. The complex grasping task can be defined as object contact control and manipulation subtasks. In this paper, object contact control subtask is defined as the ability to follow a trajectory accurately by the fingers of a gripper. The object manipulation subtask is defined in terms of maintaining a predefined applied force by the fingers on the object. A sophisticated controller is necessary since the process of grasping an object without a priori knowledge of the object's size, texture, softness, gripper, and contact dynamics is rather difficult. Moreover, the object has …


Smeared Phase Transition In A Three-Dimensional Ising Model With Planar Defects: Monte Carlo Simulations, Rastko Sknepnek, Thomas Vojta Jan 2004

Smeared Phase Transition In A Three-Dimensional Ising Model With Planar Defects: Monte Carlo Simulations, Rastko Sknepnek, Thomas Vojta

Physics Faculty Research & Creative Works

We present results of large-scale Monte Carlo simulations for a three-dimensional Ising model with short-range interactions and planar defects, i.e., disorder perfectly correlated in two dimensions. We show that the phase transition in this system is smeared, i.e., there is no single critical temperature, but different parts of the system order at different temperatures. This is caused by effects similar to but stronger than Griffiths phenomena. In an infinite-size sample there is an exponentially small but finite probability to find an arbitrary large region devoid of impurities. Such a rare region can develop true long-range order while the bulk system …


Traversal Times For Random Walks On Small-World Networks, V. M. Kenkre, Paul Ernest Parris Jan 2004

Traversal Times For Random Walks On Small-World Networks, V. M. Kenkre, Paul Ernest Parris

Physics Faculty Research & Creative Works

We study the mean traversal time tau for a class of random walks on Newman-Watts small-world networks, in which steps around the edge of the network occur with a transition rate F that is different from the rate f for steps across small-world connections. when f>>F, the mean time tau to traverse the network exhibits a transition associated with percolation of the random graph (i.e., small-world) part of the network, and a collapse of the data onto a universal curve. This transition was not observed in earlier studies in which equal transition rates were assumed for all allowed steps. …


Variational Considerations In The Study Of Carrier Transport In Organic Crystals, V. M. Kenkre, Paul Ernest Parris Jan 2004

Variational Considerations In The Study Of Carrier Transport In Organic Crystals, V. M. Kenkre, Paul Ernest Parris

Physics Faculty Research & Creative Works

A variational approach is used to investigate consequences of electron-phonon interactions between a charge carrier and multiple (specifically two) phonon branches. Phase diagrams are obtained and the nature of the transition from undressed to dressed phases of the carrier is studied with their help. No sharp transition between singly dressed and doubly dressed phases occurs. The effective carrier bandwidth, reduced by strong coupling to the high-frequency branch is found to be stable with respect to small to intermediate values of additional coupling to the low-frequency branch. This finding lends support to transport calculations based on the idea that carriers in …


Laser Writing Of Semiconductor Nanoparticles And Quantum Dots, Massimo F. Bertino, Raghuveer Reddy Gadipalli, J. Greg Story, C. G. Williams, Guo-Hui Zhang, Chariklia Sotiriou-Leventis, Akira Tokuhiro, Suchi Guha, Nicholas Leventis Jan 2004

Laser Writing Of Semiconductor Nanoparticles And Quantum Dots, Massimo F. Bertino, Raghuveer Reddy Gadipalli, J. Greg Story, C. G. Williams, Guo-Hui Zhang, Chariklia Sotiriou-Leventis, Akira Tokuhiro, Suchi Guha, Nicholas Leventis

Physics Faculty Research & Creative Works

Silica aerogels were patterned with CdS using a photolithographic technique based on local heating with infrared (IR) light. The solvent of silica hydrogels was exchanged with an aqueous solution of the precursors CdNO3 and NH4 OH, all precooled to a temperature of 5°C. Half of the bathing solution was then replaced by a thiourea solution. After thiourea diffused into the hydrogels, the samples were exposed to a focused IR beam from a continuous wave, Nd-YAG laser. The precursors reacted in the spots heated by the IR beam to form CdS nanoparticles. We lithographed features with a diameter of …


Effects Of Localization And Amplification On Intensity Distribution Of Light Transmitted Through Random Media, Alexey Yamilov, Hui Cao Jan 2004

Effects Of Localization And Amplification On Intensity Distribution Of Light Transmitted Through Random Media, Alexey Yamilov, Hui Cao

Physics Faculty Research & Creative Works

We numerically study the statistical distribution of intensity of light transmitted through quasi-one-dimensional random media by varying the dimensionless conductance g and the amount of absorption or gain. A markedly non-Rayleigh distribution is found to be well fitted by the analytical formula of Nieuwenhuizen et al. [Phys. Rev. Lett. 74, 2674 (1995)] with a single parameter g′ . We show that in the passive random system g′ is uniquely related to g , while in amplifying or absorbing random media g′ also depends on the gain or absorption coefficient.


Progress At The Heidelberg Ebit, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Christina Dimopoulou, I. N. Draganic, Daniel Fischer, Antonio J. Gonzalez, A. Lapierre, V. Mironov, Robert Moshammer, R. Soria Orts, Hiroyuki Tawara, M. Trinczek, Joachim Hermann Ullrich Jan 2004

Progress At The Heidelberg Ebit, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Christina Dimopoulou, I. N. Draganic, Daniel Fischer, Antonio J. Gonzalez, A. Lapierre, V. Mironov, Robert Moshammer, R. Soria Orts, Hiroyuki Tawara, M. Trinczek, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Two years after the relocation of the Heidelberg EBIT, several experiments are already in operation. Spectroscopic measurements in the optical region have delivered the most precise reported wavelengths for highly charged ions, in the case of the forbidden transitions of Ar XIV and Ar XV. The lifetimes of the metastable levels involved in those transitions has been determined with an error of less than 0.2%. A new, fully automatized x-ray crystal spectrometer allows systematic measurements with very high precision and reproducibility. Absolute measurements of the Lyman series of H-like ions are currently underway. Dielectronic recombination studies have yielded information on …


Renormalization-Group Analysis Of The Generalized Sine-Gordon Model And Of The Coulomb Gas For D > 3 Dimensions, I. Nandori, Ulrich D. Jentschura, Kornel Sailer, Gerhard Soff Jan 2004

Renormalization-Group Analysis Of The Generalized Sine-Gordon Model And Of The Coulomb Gas For D > 3 Dimensions, I. Nandori, Ulrich D. Jentschura, Kornel Sailer, Gerhard Soff

Physics Faculty Research & Creative Works

Renormalization-group (RG) flow equations have been derived for the generalized sine-Gordon model (GSGM) and the Coulomb gas (CG) in d ≥ 3 of dimensions by means of the Wegner-Houghton method, and by way of the real-space RG approach. The UV scaling laws determined by the leading-order terms of the flow equations are in qualitative agreement for all dimensions d ≥ 3, independent of the dimensionality, and in sharp contrast to the special case d=2. For the 4-dimensional GSGM it is demonstrated explicitly (by numerical calculations) that the blocked potential tends to a constant effective potential in the infrared limit, satisfying …


In-Situ Apparent Conductivity Measurements And Microbial Population Distribution At A Hydrocarbon-Contaminated Site, Estella A. Atekwana, D. Dale Werkema, Joseph W. Duris, Silvia Rossbach, Eliot A. Atekwana, William A. Sauck, Daniel P. Cassidy, Jay Means, Franklyn D. Legall Jan 2004

In-Situ Apparent Conductivity Measurements And Microbial Population Distribution At A Hydrocarbon-Contaminated Site, Estella A. Atekwana, D. Dale Werkema, Joseph W. Duris, Silvia Rossbach, Eliot A. Atekwana, William A. Sauck, Daniel P. Cassidy, Jay Means, Franklyn D. Legall

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We investigated the bulk electrical conductivity and microbial population distribution in sediments at a site contaminated with light nonaqueous-phase liquid (LNAPL). The bulk conductivity was measured using in-situ vertical resistivity probes; the most probable number method was used to characterize the spatial distribution of aerobic heterotrophic and oil-degrading microbial populations. The purpose of this study was to assess if high conductivity observed at aged LNAPL-impacted sites may be related to microbial degradation of LNAPL. The results show higher bulk conductivity coincident with LNAPL-impacted zones, in contrast to geoelectrical models that predict lower conductivity in such zones. The highest bulk conductivity …


Decentralized Neural Network Control Of A Class Of Large-Scale Systems With Unknown Interconnection, Wenxin Liu, Jagannathan Sarangapani, Donald C. Wunsch, Mariesa Crow Jan 2004

Decentralized Neural Network Control Of A Class Of Large-Scale Systems With Unknown Interconnection, Wenxin Liu, Jagannathan Sarangapani, Donald C. Wunsch, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

A novel decentralized neural network (DNN) controller is proposed for a class of large-scale nonlinear systems with unknown interconnections. The objective is to design a DNN for a class of large-scale systems which do not satisfy the matching condition requirement. The NNs are used to approximate the unknown subsystem dynamics and the interconnections. The DNN is designed using the back stepping methodology with only local signals for feedback. All of the signals in the closed loop (system states and weights estimation errors) are guaranteed to be uniformly ultimately bounded and eventually converge to a compact set.


Biup3: Boundary Topological Invariant Of 3d Objects Through Front Propagation At A Constant Speed, Xiaoqing Frank Liu Jan 2004

Biup3: Boundary Topological Invariant Of 3d Objects Through Front Propagation At A Constant Speed, Xiaoqing Frank Liu

Computer Science Faculty Research & Creative Works

Topological features constitute the highest abstraction in object representation. Euler characteristic is one of the most widely used topological invariants. The computation of the Euler characteristic is mainly based on three well-known mathematical formulae, which calculate either on the boundary of object or on the whole object. However, as digital objects are often non-manifolds, none of the known formulae can correctly compute the genus of digital surfaces. In this paper, we show that a new topological surface invariant of 3D digital objects, called BIUP/sup 3/, can be obtained through a special homeomorphic transform: front propagation at a constant speed. BIUP/sup …


Interactive Dna Sequence And Structure Design For Dna Nanotechnology And Dna Computation, Mingjun Zhang, Chaman Sabharwal, Weimin Tao, Tzyh-Jong Tarn, Ning Xi, Guangyong Li Jan 2004

Interactive Dna Sequence And Structure Design For Dna Nanotechnology And Dna Computation, Mingjun Zhang, Chaman Sabharwal, Weimin Tao, Tzyh-Jong Tarn, Ning Xi, Guangyong Li

Computer Science Faculty Research & Creative Works

DNA sequence and structure design are very important for DNA nanotechnology and DNA computation. A computer aided design tool is needed for exploring DNA sequence and structure of interests before experimental synthesis, which is a very time and labor consuming process. In this paper, an interactive DNA sequence and structure design software tool called DNA shop is proposed and implemented.


Priority Assessment Of Software Requirements From Multiple Perspectives, Xiaoqing Frank Liu, Chandra Sekhar Veera, Yan Sun, Kunio Noguchi, Yuji Kyoya Jan 2004

Priority Assessment Of Software Requirements From Multiple Perspectives, Xiaoqing Frank Liu, Chandra Sekhar Veera, Yan Sun, Kunio Noguchi, Yuji Kyoya

Computer Science Faculty Research & Creative Works

The development of complex software systems involves collecting software requirements from various stakeholders. Often stakeholder perceptions conflict during the requirements elicitation phase. An effective technique to resolve such a conflict is needed. We presented a framework that prioritizes software requirements gathered from multiple stakeholders by incorporating inter-perspective relationships, which is not addressed by existing priority assessment techniques. We use a relationship matrix to analyze the impact between requirements and facilitate the integration process which assesses their priorities based on their relationships from multiple perspectives. It allows the development team to resolve conflicts effectively and concentrate their valuable time and resources …


2,4-Dinitrophenylhydrazones Of 2,4-Dihydroxybenzaldehyde, 2,4-Dihydroxyacetophenone And 2,4-Dihydroxybenzophenone, Russell G. Baughman, Kenneth L. Martin, Rajendra K. Singh, James O. Stoffer Jan 2004

2,4-Dinitrophenylhydrazones Of 2,4-Dihydroxybenzaldehyde, 2,4-Dihydroxyacetophenone And 2,4-Dihydroxybenzophenone, Russell G. Baughman, Kenneth L. Martin, Rajendra K. Singh, James O. Stoffer

Chemistry Faculty Research & Creative Works

In 2,4-dihydroxybenzaldehyde 2,4-dinitrophenylhydrazone N,N-dimethylformamide solvate (or 4-[(2,4-dinitrophenyl)-hydrazonomethyl]benzene-1,3-diol N,N-dimethylformamide solvate


Adaptive Force-Balancing Control Of Mems Gyroscope With Actuator Limits, Mohammed Hameed, Jagannathan Sarangapani Jan 2004

Adaptive Force-Balancing Control Of Mems Gyroscope With Actuator Limits, Mohammed Hameed, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This work presents an adaptive force-balancing control (AFBC) scheme with actuator limits for a MEMS Z-axis gyroscope. The purpose of the adaptive force-balancing control is to identify major fabrication imperfections so that they are properly compensated unlike the case of conventional force-balancing controlled gyroscope. The proposed AFBC scheme controls the vibratory modes of the proof mass while ensuring that the control input satisfies the magnitude constraints and the performance of the gyroscope is enhanced in the presence of fabrication uncertainties. Consequently, commonly reported problems of MEMS gyroscope such as quadrature compensation, drive and sense axes frequency tuning are not needed …


Highest-Quality Modes In Disordered Photonic Crystals, Alexey Yamilov, Hui Cao Jan 2004

Highest-Quality Modes In Disordered Photonic Crystals, Alexey Yamilov, Hui Cao

Physics Faculty Research & Creative Works

We studied the modes of the highest-quality factor Qm in disordered photonic crystals. by varying the strength of disorder, we identified five different scaling regimes of the ensemble averaged (Qm) with the system size. For sufficiently large systems, (Qm) reaches the maximum at some finite degree of disorder, where its value is comparable to the quality factor of an intentionally introduced single defect at the center of a photonic band gap. Near this optimal degree of disorder, we predict a superexponential increase of (Qm) with the system size, due to migration of the frequencies of the highest-quality modes toward the …


Kinetics Of Binary Nucleation Of Vapors In Size And Composition Space, Sergey P. Fisenko, Gerald Wilemski Jan 2004

Kinetics Of Binary Nucleation Of Vapors In Size And Composition Space, Sergey P. Fisenko, Gerald Wilemski

Physics Faculty Research & Creative Works

We reformulate the kinetic description of binary nucleation in the gas phase using two natural independent variables: the total number of molecules g and the molar composition x of the cluster. The resulting kinetic equation can be viewed as a two-dimensional Fokker-Planck equation describing the simultaneous Brownian motion of the clusters in size and composition space. Explicit expressions for the Brownian diffusion coefficients in cluster size and composition space are obtained. For characterization of binary nucleation in gases three criteria are established. These criteria establish the relative importance of the rate processes in cluster size and composition space for different …


Order-Parameter Symmetry And Mode-Coupling Effects At Dirty Superconducting Quantum Phase Transitions, Rastko Sknepnek, Thomas Vojta, Rajesh Narayanan Jan 2004

Order-Parameter Symmetry And Mode-Coupling Effects At Dirty Superconducting Quantum Phase Transitions, Rastko Sknepnek, Thomas Vojta, Rajesh Narayanan

Physics Faculty Research & Creative Works

We derive an order-parameter field theory for a quantum phase transition between a disordered metal and an exotic (non- s -wave) superconductor. Mode coupling effects between the order parameter and other fermionic soft modes lead to an effective long-range interaction between the anomalous density fluctuations which is reflected in singularities in the free energy functional. However, this long-range interaction is not strong enough to suppress disorder fluctuations. The asymptotic critical region is characterized by run-away flow to large disorder. For weak coupling, this asymptotic region is very narrow. It is preempted by a wide crossover regime with mean-field critical behavior …


Discrete-Time Neural Network Output Feedback Control Of Nonlinear Systems In Non-Strict Feedback Form, Pingan He, Jagannathan Sarangapani Jan 2004

Discrete-Time Neural Network Output Feedback Control Of Nonlinear Systems In Non-Strict Feedback Form, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

An adaptive neural network (NN)-based output feedback controller is proposed to deliver a desired tracking performance for a class of discrete-time nonlinear systems, which is represented in non-strict feedback form. The NN backstepping approach is utilized to design the adaptive output feedback controller consisting of: 1) a NN observer to estimate the system states with the input-output data, and 2) two NNs to generate the virtual and actual control inputs, respectively. The non-causal problem in the discrete-time backstepping design is avoided by using the universal NN approximator. The persistence excitation (PE) condition is relaxed both in the NN observer and …


Distributed Power Control Of Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani Jan 2004

Distributed Power Control Of Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel distributed power control (DPC) scheme for cellular networks in the presence of radio channel uncertainties such as path loss shadowing, and Rayleigh fading is presented. Since these uncertainties can attenuate the received signal strength and can cause variations in the received Signal-to-lnterference ratio (SIR), the proposed DPC scheme maintains a target SIR at the receiver provided the uncertainty is slowly varying with time. The DPC estimates the time varying nature of the channel quickly and uses the information to arrive at a suitable transmitter power value . Further, the standard assumption of a constant interference during a link's …