Pencil in the Hand of the Creator?An Igbo Hermeneutic Rebuttal of Wale Adenuga’s Concept of the Human Person

The thesis of this paper is a refutation of Wale Adenuga’s claim that the human person is nothing but a pencil in the hand of the creator.The paper adopts a hermeneutical approach from an Igbo conception of the human person.It posits that in Igbo worldview,the human person occupies a central position because mankind is at the very centre of existence;hence is seen as the goodness or beauty of life(mma ndu)or the good or beauty that is(mma du{di}).While conceding the plausibility of a pencil being capable of doing great things when guided by a good hand,the paper maintains that from the point of view of Igbo ontology,the human person is distinctively more than a mere pencil in the hand of the creator because mankind is endowed with high intellectual capacity,freedom,and creativity on the basis of which it seen as both the beauty that is(mma du)or the beauty or goodness of life(mma ndu).Thus,the paper concludes that the fact that the human person is endowed with these attributes provides rational grounds to render Wale Adenuga’s concept of the human person as“nothing but a pencil in the hand of the creator”futile.

基于Matrix Pencil的OFDM信号的TOA/AOA定位

为提高估计精度,提出一种基于低复杂度的矩阵束方法(MPM)的OFDM信号超分辨率TOA/AOA二维定位方法。首先,对信道频率响应(CFR)采用MPM方法进行时延估计,得出首径(FAP)时延,即OFDM信号的TOA估计;然后,对天线接收信号的频域阵列信号使用同样的算法进行AOA/DOA估计;最后,联合TOA、AOA估计结果在二维平面内确定目标的位置。由于载波间的相关性和相干多径的影响,使AOA估计的RMSE偏差比TOA估计大,所以对TOA估计过程中的各径幅值,设置权值对非首径的幅值进行抑制,减少对后续首径AOA估计的影响。利用OFDM信号进行仿真,其结果表明,非首径幅值抑制方法能明显提高AOA估计精度和无偏性,使整体定位误差明显改善,满足单基站或接入点室内定位的需要。

Collection efficiency of a monitor parallel plate ionization chamber for pencil beam scanning proton therapy

The collection efficiency of monitor parallel plate ionization chambers is the main uncertainty in the beam control of pencil beam scanning systems.Existing calculation methods for collection efficiency in photon or passive scattering proton systems have not considered the characteristics of non-uniform charge density in pencil beam scanning systems.In this study,Boag’s theory was applied to a proton pencil beam scanning system.The transverse distribution of charge density in the ionization chamber was considered to be a Gaussian function and an analytical solution was derived to calculate collection efficiency in the beam spot area.This calculation method is called the integral method and it was used to investigate the effects of beam parameters on collection efficiency.It was determined that collection efficiency is positively correlated with applied voltage,beam size,and beam energy,but negatively correlated with beam current intensity.Additionally,it was confirmed that collection efficiency is improved when the air filling the monitor parallel plate ionization chamber is replaced with nitrogen.

High-Performance Solid-State Supercapacitors Fabricated by Pencil Drawing and Polypyrrole Depositing on Paper Substrate

A solid-state powerful supercapacitor(SC) is fabricated with a substrate of Xerox paper. Its current collector based on a foldable electronic circuit is developed by simply pencil drawing. Thin graphite sheets on paper provide effective channels for electron transmission with a low resistance of 95 X sq-1. The conductive organic material of polypyrrole coated on thin graphite sheets acts as the electrode material of the device. The as-fabricated SC exhibits a high specific capacitance of 52.9 F cm-3at a scan rate of 1 m V s-1. An energy storage unit fabricated by three full-charged series SCs can drive a commercial light-emitting diode robustly. This work demonstrated a simple, versatile and costeffective method for paper-based devices.

A survey of incidental ocular trauma by pencil and pen

AIM：To determine characteristic features of ocular trauma resulted from self-trauma by writing instruments among pediatric population.METHODS：Thirty-six children who suffered from selfinflicted ocular trauma with a writing instrument were included in this prospective cross-sectional study.RESULTS：The mean age was 5.6±2.7y with male：female ratio of 1.77.The right eye was involved two times more than the left eye.The superomedial（55.5%）and inferomedial（30.6%）quadrants were the most common sites of injury.The leading culprit was colored pencils（44.4%）.During surgical exploration,no foreign body（FB）was found in 25（69.4%）patients while an FB was found in 11（30.5%）patients.Brain injury was present in two patients（5.6%）and only in superomedial quadrant injuries.Zone 1 was the most common site for ocular trauma associated with penetrating injury.The mean ocular trauma score（OTS）in penetrating injuries was 3.8±1.2.The best corrected visual acuity（BCVA）was 0.3±0.6 upon admittance and 0.08±0.21 after one year.The final BCVA was significantly correlated with the entrance site,better final BCVA was found in nasal entrance site（P〈0.05）.CONCLUSION：The ophthalmologists should keep a high index of suspicion to rule out penetrating eye injuries related to writing instruments in a young uncooperative child.Brain injury is a life-threatening event that should be ruled out by appropriate imaging.Medial canthal area as the most common site needs an especial attention in writing instrument injuries.

Reformatted method for two-dimensional detector arrays measurement data in proton pencil beam scanning

The spatial resolution of a commercial two-dimensional(2D)ionization chamber(IC)array is limited by the size of the individual detector and the center-to-center distance between sensors.For dose distributions with areas of steep dose gradients,inter-detector dose values are derived by the interpolation of nearby detector readings in the conventional mathematical interpolation of 2D IC array measurements.This may introduce significant errors,particularly in proton spot scanning radiotherapy.In this study,by combining logfile-based reconstructed dose values and detector measurements with the Laplacian pyramid image blending method,a novel method is proposed to obtain a reformatted dose distribution that provides an improved estimation of the delivered dose distribution with high spatial resolution.Meanwhile,the similarity between the measured original data and the downsampled logfilebased reconstructed dose is regarded as the confidence of the reformatted dose distribution.Furthermore,we quantify the performance benefits of this new approach by directly comparing the reformatted dose distributions with 2D IC array detector mathematically interpolated measurements and original low-resolution measurements.The result shows that this new method is better than the mathematical interpolation and achieves gamma pass rates similar to those of the original low-resolution measurements.The reformatted dose distributions generally yield a confidence exceeding 95%.

基于Matrix Pencil的低频振荡辨识及PSS优化配置研究

在互联系统中,低频振荡问题越来越成为影响电力系统稳定的重要因素。广域测量系统(WAMS)的发展和应用使得低频振荡的在线辨识和PSS配置及参数优化成为可能。本文探讨了在已知干扰情况下,利用测量数据构造矩阵,基于Matrix Pencil算法来进行电力系统低频振荡模式分析,建立多输入输出系统的低阶近似的辨识传递函数,并在此基础上利用奇异值分解(SVD)的方法来分析PSS优化配置问题。通过经4机2区域系统的仿真实验研究表明,基于Matrix Pencil辨识算法能建立准确的低阶近似传递函数,奇异值分解的方法能有效分析出PSS最佳配置地点。

Frequency Domain Filtering SAR Interferometric Phase Noise Using the Amended Matrix Pencil Model

Interferometric phase filtering is one of the key steps in interferometricsynthetic aperture radar (InSAR/SAR). However, the ideal filtering results are difficult toobtain due to dense fringe and low coherence regions. Moreover, the InSAR/SAR datarange is relatively large, so the efficiency of interferential phase filtering is one of themajor problems. In this letter, we proposed an interferometric phase filtering methodbased on an amended matrix pencil and linear window mean filter. The combination ofthe matrix pencil and the linear mean filter are introduced to the interferometric phasefiltering for the first time. First, the interferometric signal is analyzed, and theinterferometric phase filtering is transformed into a local frequency estimation problem.Then, the local frequency is estimated using an amended matrix pencil at a window. Thelocal frequency can represent terrain changes, thus suggesting that the frequency can beaccurately estimated even in dense fringe regions. Finally, the local frequency is filteredby using a linear window mean filter, and the filtered phase is recovered. The proposedmethod is calculated by some matrices. Therefore, the computational complexity isreduced, and the efficiency of the interferometric phase filtering is improved.Experiments are conducted with simulated and real InSAR data. The proposed methodexhibits a better filtering effect and an ideal efficiency as compared with the traditionalfiltering method.

Evaluation of Pencil Lead Based Electrodes for Electrocardiogram Monitoring in Hot Spring

Electrocardiogram(ECG)electrodes are conductive pads applied to the skin to measure cardiac activity.Ag/AgCl electrodes are the commercial product which widely used to obtain ECGs.When monitoring the ECG in a hot spring,Ag/AgCl electrodes must be waterproofed;however,this is time-consuming,and the adhesive may tear the skin on removal.For solving the problem,we developed the carbon pencil lead(CPL)electrodes for use in hot springs.Both CPL and Ag/AgCl electrodes were connected to ECG100C’s cables.The Performance was evaluated in three conditions as following:hot spring water with and without bubble,and in cold water.In each environment,the procedure was followed by three different protocols that are recording from the dry condition,hot spring water immersion with and without movement,post hot spring water condition.Under dry and wet conditions,both electrodes can obtain the waveform of the ECG signal in which all PQRST waves were identifiable.Nevertheless,the signal quality of both types of electrodes was different in water immersion with and without movement.The overall morphology obtained by Ag/AgCl electrodes was unstable higher than that of CPL electrodes in immersion without movement condition.The CPL electrodes provided better ECG waveform quality compared to Ag/AgCl electrodes in which the ECG signal had high waveforms distortion in water immersion with movement condition.

Ultra-light and flexible pencil-trace anode for high performance potassium-ion and lithium-ion batteries

Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple friction drawing on filter paper with a commercial 8 B pencil.Compared with the traditional anode using copper foil as current collector, this innovative current-collector-free design presents capacity improvement of over 200% by reducing the inert weight of the electrode. The as-prepared pencil-trace electrode exhibits excellent rate performance in potassium-ion batteries(KIBs), significantly better than in lithium-ion batteries(LIBs), with capacity retention of 66% for the KIB vs. 28% for the LIB from 0.1 to 0.5 A g^(-1). It also shows a high reversible capacity of ～230 mAh g^(-1) at 0.2 A g^(-1), 75% capacity retention over350 cycles at 0.4 A g^(-1)and the highest rate performance(based on the total electrode weight) among graphite electrodes for K+ storage reported so far.

Correction of failure in antenna array using matrix pencil technique

In this paper a non-iterative technique is developed for the correction of faulty antenna array based on matrix pencil technique（MPT）. The failure of a sensor in antenna array can damage the radiation power pattern in terms of sidelobes level and nulls. In the developed technique, the radiation pattern of the array is sampled to form discrete power pattern information set. Then this information set can be arranged in the form of Hankel matrix（HM） and execute the singular value decomposition（SVD）. By removing nonprincipal values, we obtain an optimum lower rank estimation of HM. This lower rank matrix corresponds to the corrected pattern. Then the proposed technique is employed to recover the weight excitation and position allocations from the estimated matrix. Numerical simulations confirm the efficiency of the proposed technique, which is compared with the available techniques in terms of sidelobes level and nulls.

ON THE GENERALIZED RESOLVENT OF LINEAR PENCILS IN BANACH SPACES

. Utilizing the stability characterizations of generalized inverses of linear operator, we investigate the existence of generalized resolvent of linear pencils in Banach spaces. Some practical criterions for the existence of generalized resolvents of the linear pencil λ→ T - λS are provided and an explicit expression of the generalized resolvent is also given. As applications, the characterization for the Moore-Penrose inverse of the linear pencil to be its generalized resolvent and the existence of the generalized resolvents of linear pencils of finite rank operators, Fredholm operators and semi-Fredholm operators are also considered. The results obtained in this paper extend and improve many results in this area.

Robustness Evaluation of a Novel Proton Beam Geometry for Head and Neck Patients Treated with Pencil Beam Scanning Therapy

Background: To evaluate the robustness of head and neck treatment using proton pencil beam scanning (PBS) technique with respect to range uncertainty (RU) and setup errors (SE), and to establish a robust PBS planning strategy for future treatment. Methods and Materials: Ten consecutive patients were planned with a novel proton field geometry (combination of two posterior oblique fields and one anterior field with gradient dose match) using single-field uniform dose (SFUD) planning technique and the proton plans were dosimetrically compared to two coplanar arc VMAT plans. Robustness of the plans, with respect to range uncertainties (RU = ± 3% for proton) and setup errors (SE = 2.25 mm for proton and VMAT), in terms of deviations to target coverage (CTV D98%) and OAR doses (max/mean), were evaluated and compared for each patient under worst case scenarios. Results: Dosimetrically, PBS plans provided better sparing to larynx (p = 0.005), oral cavity (p < 0.001) and contralateral parotid (p = 0.004) when compared to VMAT. CTV D98% variations were higher from SE than from RU for proton plans (-1.1% ± 1.3 % vs -0.4% ± 0.7% for nodal CTV and -1.4% ± 1.2 vs -0.4% ± 0.5% % for boost CTV). Overall, the magnitudes of variation of CTV D98% to combined SE and RU were found to be similar to the impact of the SE on the VMAT plans (-1.6% ± 1.9% vs -1.7% ± 1.4% for nodal CTV and -1.9% ± 1.6% vs -1.3% ± 1.5% for boost CTV). Compared to VMAT, a larger range of relative dose deviations were found for OARs in proton plans, but safe doses were maintained for cord (41.8 ± 3.6 Gy for PBS and 41.7 ± 3.9 Gy for VMAT) and brainstem (35.2 ± 8.4 Gy for PBS and 36.2 ± 5.1 Gy for VMAT) in worst case scenarios. Conclusions: Compared to VMAT, proton plans containing three SFUD fields with superior-inferior gradient dose matching had improved sparing to larynx, contralateral parotid and oral cavity, while providing similar robustness of target coverage. Evaluation of OAR dose robustness showed higher sensitivities to uncertainties for proton plans, but safe dose levels were maintained for cord and brainstem.

Pencil Beam Grid Antenna Array for Hyperthermia Breast Cancer Treatment System

In this paper, efficient, high gain and pencil beam grid antenna array is proposed for hyperthermia breast cancer therapy system. The proposed antenna bandwidth extends from 4.8 GHz to 4.9 GHz at resonant frequency of 4.86 GHz. This frequency band has been reported for the breast cancer hyperthermia therapy. The grid long and short sides are responsible for the undesired cross-polarized radiation and desired copolarized radiation, respectively. The unsuitability of the conventional grid antenna array is ensured by investigating its radiation properties. The proposed grid antenna array short side width is varied and its long side width is kept wide as possible to enhance the radiation properties and to reduce the losses. Also, a reflector has been used for gain enhancement purpose. The proposed grid antenna array achieves side lobe level and 3 dB beam width of —27.9 dB and 25.9° for the E-plane and —27.9 dB and 26.3° for the H-plane, respectively. The breast phantom is irradiated by both proposed and conventional grid antenna arrays for 10 minutes. The proposed grid antenna array achieves 8°C temperature increase within the breast phantom area compared to 2°C temperature increase for conventional one. The proposed grid antenna array is highly efficient, high gain and light weight, and it has a very suitable radiation property for hyperthermia breast cancer therapy.

Amperometric Determination of Serum Cholesterol with Pencil Graphite Rod

A cholesterol oxidase from Streptomycin sp. was immobilized onto pencil graphite rod and employed for amperometric determination of serum cholesterol. The method has the advantage over earlier amperometric methods that it requires low potential to generate electrons from H2O2, which does not allow ionization of serum substances. The optimum working conditions of amperometric determination were pH 6.8, 25?C and 30 s. The current measured was in proportion to cholesterol concentration ranging from 1.29×10-3 to 10.33×10-3 M. Minimum detection limit of the method was 0.09 ×10-3 M. Mean analytical recovery of added cholesterol (100 mg/dl and 200 mg/dl) in serum was 85.0% & 90.0% respectively. Within batch and between batch coefficients of variations were 1.59% & 4.15% respectively. A good correlation (r = 0.99) was obtained between serum cholesterol values by standard enzymic colorimetric method and the present method. No interference by metabolites was observed in the method. The enzyme electrode was reused 200 times over a period of 25 days, when stored at 4?

Determination of Dopamine in Presence of Uric Acid at Poly (Eriochrome Black t) Film Modified Graphite Pencil Electrode

A simple commercial graphite pencil electrode was used to investigate the electrochemical oxidation of dopamine. The electropolymerised film of eriochrome black t was prepared on the surface of graphite pencil electrode by using cyclic voltammetry technique. The prepared electrode exhibits an excellent electrocatalytical activity towards the determination of dopamine. The effects of concentration, pH and scan rate were investigated. Simultaneous detection of dopamine and uric acid was investigated by using both cyclic voltammetric and differential pulse voltammetry technique. The modified electrode was also used for the detection of dopamine in injection.

On a Boundary Value Problem for a Polynomial Pencil of the Sturm-Liouville Equation with Spectral Parameter in Boundary Conditions

The boundary value problem with a spectral parameter in the boundary conditions for a polynomial pencil of the Sturm-Liouville operator is investigated. Using the properties of the transformation operators for such operators, the asymptotic formulas for eigenvalues of the boundary value problem are obtained.

Evaluation of Single Field Uniform Dose (SFUD) Proton Pencil Beam Scanning (PBS) Planning Strategy for Lung Mobile Tumor Using a Digital Phantom

Purpose: To quantitatively evaluate four different Proton SFUD PBS initial planning strategies for lung mobile tumor. Methods and Materials: A virtual lung patient’s four-dimensional computed tomography (4DCT) was generated in this study. To avoid the uncertainties from target delineation and imaging artifacts, a sphere with diameter of 3 cm representing a rigid mobile target (GTV) was inserted into the right side of the lung. The target motion is set in superior-inferior (SI) direction from ?5 mm to 5 mm. Four SFUD planning strategies were used based on: 1) Maximum-In-tensity-Projection Image (MIP-CT);2) CT_average with ITV overridden to muscle density (CTavg_muscle);3) CT_average with ITV overridden to tumor density (CTavg_tumor);4) CT_average without any override density (CTavg_only). Dose distributions were recalculated on each individual phase and accumulated together to assess the “actual” treatment. To estimate the impact of proton range uncertainties, +/?3.5% CT calibration curve was applied to the 4DCT phase images. Results: Comparing initial plan to the dose accumulation: MIP-CT based GTV D98 degraded 2.42 Gy (60.10 Gy vs 57.68 Gy). Heart D1 increased 6.19 Gy (1.88 Gy vs 8.07 Gy);CTavg_tumor based GTV D98 degraded 0.34 Gy (60.07 Gy vs 59.73 Gy). Heart D1 increased 2.24 Gy (3.74 Gy vs 5.98 Gy);CTavg_muscle based initial GTV D98 degraded 0.31 Gy (60.4 Gy vs 60.19 Gy). Heart D1 increased 3.44 Gy (4.38 Gy vs 7.82 Gy);CTavg_only based Initial GTV D98 degraded 6.63 Gy (60.11 Gy vs 53.48 Gy). Heart D1 increased 0.30 Gy (2.69 Gy vs 2.96 Gy);in the presence of ±3.5% range uncertainties, CTavg_tumor based plan’s accumulated GTV D98 degraded to 57.99 Gy (+3.5%) 59.38 Gy (?3.5%), and CTavg_muscle based plan’s accumulated GTV D98 degraded to 59.37 Gy (+3.5%) 59.37 Gy (?3.5%). Conclusion: This study shows that CTavg_Tumor and CTavg_Muscle based planning strategies provide the most robust GTV coverage. However, clinicians need to be aware that the actual dose to OARs at distal end of target may increase. The study also indicates that the current SFUD PBS planning strategy might not be sufficient to compensate the CT calibration uncertainty.

Analysis of the nonlinear dynamic characteristics of two-phase flow based on an improved matrix pencil method

Gas–liquid two-phase flow is complex and has uncertainty in phase interfaces, which make the two-phase flow look very complicated. Even though the flow behavior(e.g. coalescence, crushing and separation) of single bubble or bubble groups in the liquid phase looks random, combining some established characteristics and methodologies can find regularities among the randomness. In order to excavate the nonlinear dynamic characteristics of gas–liquid two-phase flow, the authors developed an improved matrix pencil(IMP) method to analyze the pressure difference signals of the two-phase flow. This paper elucidates the influence of signal length on MP calculation results and the anti-noise-interference ability of the MP method. An IMP algorithm was applied to the fluctuation signals of gas–liquid two-phase flow to extract the mode frequency and damping ratio, which were combined with the component energy index(CEI) entropy to identify the different flow patterns. It is also found that frequency, damping ratio, CEI entropy and stability diagram together not only identify flow patterns, but also provide a new way to examine and understand the evolution mechanism of physical dynamics embedded in flow patterns. Combining these characteristics and methods, the evolution of the nonlinear dynamic physical behavior of gas bubbles is revealed.