Exploitation of Liquefied Natural Gas Cold Energy in Floating Storage Regasification Units

[Abstract] This paper aims to review regasification technology installed in Floating Storage Regasification Units (FSRUs) and the potential offered by the exploitation of cold energy from liquefied natural gas (LNG) in these vessels. The assessment describes the main characteristics of regasification systems along with their respective advantages and limitations. Regasification systems in direct exchange (seawater and steam) and systems with intermediate fluids that use propane or water-glycol in the heat transfer process are studied. In recent years, water-glycol systems have cornered the market. The mixture, besides reducing the risk of freezing, is non-flammable, economical and highly available. Thermodynamic analysis of the regasification process shows that LNG cold energy is the main source of residual energy in these vessels; the specific energy and exergy content is more than double that of engine exhaust gases. Exploitation of this cold energy in power cycles could significantly reduce FSRUs harmful emissions and electrical energy could even be exported to shore. The organic Rankine cycle technology is the most well-known and widely studied, although scientific literature is scarce and there is a need to propose new regasification systems with cold energy exploitation that can be adopted on these vessels

ANALISIS KESALAHAN PENGGUNAAN TENKA NO SETSUZOKUSHI SOSHITE, SOREKARA, SORENI, DAN SONOUE DALAM KALIMAT BAHASA JEPANG

Setsuzokushi (konjungsi) mempunyai peranan penting dalam pembentukan kalimat bahasa Jepang. Walaupun penggunaan gramatikalnya benar, namun apabila pemakaian konjungsinya tidak sesuai maka akan merubah makna kalimat yang dimaksud. Banyaknya jenis setsuzokushi yang memiliki makna yang hampir sama namun memiliki fungsi dan penggunaan yang berbeda-beda, menyebabkan pembelajar bahasa Jepang sering melakukan kesalahan. Penelitian dengan judul “Analisis Kesalahan Pengunaaan Tenka no Setsuzokushi Soshite, Sorekara, Soreni, dan Sonoue dalam Kalimat Bahasa Jepang” ini bertujuan untuk mengetahui persentase kesalahan, kesalahan apa saja yang muncul, dan faktor penyebab terjadinya kesalahan penggunaan tenka no setsuzokushi soshite, sorekara, soreni, dan sonoue dalam kalimat bahasa Jepang pada mahasiswa semester VI DPBJ UPI Tahun Akademik 2017/2018 sebanyak 46 orang. Metode yang digunakan adalah metode deskriptif. Teknik pengumpulan data menggunakan teknik one shoot model (pengambilan data satu kali dalam satu waktu) dengan tiga buah instrumen yaitu tes, angket dan wawancara. Data yang diperoleh berupa data kuantitatif dan kualitatif. Hasil penelitian menunjukkan kesalahan dalam fungsi dan makna setsuzokushi soshite yang menyatakan hasil/kesimpulan (sono kekka) sebesar 71% sebagai kesalahan paling banyak. Sedangkan kesalahan yang paling sedikit sebesar 46,7% adalah kesalahan gramatikal setsuzokushi sorekara yang berupa kalimat bentuk perintah dan ajakan (-tekudasai, -masho). Faktor penyebab kesalahan, diantaranya adalah penyamarataan berlebihan sebesar 58%, penerapan kaidah yang tidak lengkap sebesar 28%, pengabaian batas-batas kaidah bahasa 11%, dan salah menghipotesiskan konsep sebesar 3%. ;---Conjuction have an important role in the formation of Japanese sentences. In the case the grammatical stuctures is correct, but if the conjunction is not appropriate, it will change the meaning of the sentences. Many types of setsuzokushi which have a same meaning, yet have a different function, causing the learner of Japanese language often makes mistakes. A research entitled “Error Analysis of Addition Conjunction Usage Soshite, Sorekara, Soreni, and Sonoue in Japanese Sentences” aims to determine the percentage of errors, student’s error that might emerge, and to identify factor which caused error addition conjuction usage of Soshite, Sorekara, Soreni, and Sonoue in Japanese sentences on 6th semester of Japanese Education Departement of Indonesia University of Education students on academic year 2017/2018 as many as 46 persons. Descriptive method was used in this research. Data collected by using one shoot model technique (one time in one period of time) through test, questionnaire and interview as instruments. Data obtained in form of quantitative and qualitative. The results shown that error in the function and meaning of setsuzokushi soshite which express the conclution (71%) as the most mistake. While, grammar error of setsuzokushi sorekara which shows imperative sentence and invitation sentence (-tekudasai, -masho). Factor of errors are overgeneralization (58%), incomplete application of rules (28%), ignorance of rule restriction (11%), and false concept hypothesized (3%). ;---文と文をつなぐ接着剤の役割を担う「接続詞」は日本語の文章で極めて重要な役割を果たす。文章において間違い接続詞を付けば、文法的が正しいにもかかわらず、意味が変わるようになった。更に、ほぼ同じ意味であるが、接続詞は機能及び用法が異なるので、日本語の学習者はしばしば間違いをしてしまう。添加の接続詞の⎾そして⏌、⎾それから⏌、⎾それに⏌及び⎾そのうえ⏌の誤用分析という本研究の題名は誤用の割合を知り、どのような誤用が浮かび上がったこと、2017・2018年度インドネシア教育大学の日本語教育学科の第六学期の学生に対して日本語の文章で添加の接続詞の⎾そして⏌、⎾それから⏌、⎾それに⏌及び⎾そのうえ⏌の誤用の起こった原因、そういう目的を持っている。本研究の分析方法はデスクリプティブ法を使用する。One shoot model ⎾一度に1回のデータ検索⏌というデータ収集技術を使用し、研究のインストゥルメンとしてアンケートとテストとインタビューを選んだのである。その結果、最大の誤用として71％に結果・結論（その結果）を述べている⎾そして⏌の機能と意味を示している。それに対して、最小の誤用として46,7%に命令形・意志形(～て下さい、～ましょう)を述べている⎾それから⏌の文法的であった。誤用の原因は過剰規則(58%)、不定全な規則適用(28%)、不規則な制限ルール(11%)および推量の誤解(3%)を占めている

A two phase successive cancellation decoder architecture for polar codes

We propose a two-phase successive cancellation (TPSC) decoder architecture for polar codes that exploits the array-code property of polar codes by breaking the decoding of a length-TV polar code into a series of length-√ L decoding cycles. Each decoding cycle consists of two phases: a first phase for decoding along the columns and a second phase for decoding along the rows of the code array. The reduced decoder size makes it more affordable to implement the core decoder logic using distributed memory elements consisting of flip-flops (FFs), as opposed to slower random access memory (RAM), leading to a speed up in clock frequency. To minimize the circuit complexity, a single decoder unit is used in both phases with minor modifications. The re-use of the same decoder module makes it necessary to recall certain internal decoder state variables between decoding cycles. Instead of storing the decoder state variables in RAM, the decoder discards them and calculates them again when needed. Overall, the decoder has O(√ L) circuit complexity excluding RAM, and a latency of approximately 2.57V. A RAM of size O(N) is needed for storing the channel log-likelihood variables and the decoder decision variables. As an example of the proposed method, a length N = 214 bit polar code is implemented in an FPGA and the synthesis results are compared with a previously reported FPGA implementation. The results show that the proposed architecture has lower complexity, lower memory utilization with higher throughput, and a clock frequency that is less sensitive to code length. © 2013 IEEE

Seismic Site Response of Partially Saturated Soil Layers

Accurate prediction of seismic ground response plays a vital role in earthquake-resistant, sustainable, and cost-effective design of infrastructure. Seismic response of unsaturated soil layers may differ from that of saturated or dry soil deposits. Importantly, surficial soil layers are often partially water-saturated, however, site-specific design procedures only consider ground in either dry or fully saturated conditions. Further, seasonal water table fluctuation introduces additional uncertainty in site-specific response analysis. This research investigates the effect of soil-water interaction on seismic site response of soil layers both experimentally and numerically. To that end, initially, preliminary numerical analyses were performed using the DEEPSOIL software considering uniform suction profiles where partial saturation was considered by changing the unit weight and dynamic soil properties as a function of degree of saturation. Further, a set of centrifuge experiments were conducted to study the influence of partial saturation on seismic response of sand layers under scaled Northridge and Kobe earthquake motions. Steady state infiltration was implemented to control and provide uniform degrees of saturation profiles in depth. Partial saturation led to higher surface-to-base motion intensity amplification than dry conditions; especially in low period ranges. On average, the amplification of peak ground acceleration was inversely proportional to degree of saturation at surface, demonstrating higher amplifications at lower degrees of saturation. It also varied with depth, showing higher values for unsaturated conditions near the ground level. The lateral deformation and surface settlement of partially saturated sand layers with higher stiffness were generally lower than that in dry soil. Although neglecting the effect of partial saturation in sand layers might be conservative with respect to seismic deformations, it may result in underestimating the surface design acceleration spectra. To assess the uncertainty in site response analysis due to water table fluctuation, further parametric analyses were performed using DEEPSOIL program. Water table fluctuations considerably affected the seismic response of sand and silt layers, with a more significant divergence in sandy soils. Variations in small-strain shear modulus and unit weight, due to water table fluctuation, led to considerable change in site response, while the change in damping and modulus reduction factor caused insignificant difference in acceleration amplification, mainly due to the incompetency of their formulations to account for partial saturation

Area-Efficient Hardware Implementation of the Optimal Ate Pairing over BN curves.

To have an efficient asymmetric key encryption scheme such as elliptic curves, hyperelliptic curves, pairing etc., we have to go through an arithmetic optimization then a hardware one. Taking into consideration restricted environments’ compromises, we should strike a balance between efficiency and memory resources. For this reason, we studied the mathematical aspect of pairing computation and gave new development of the methods that compute the hard part of the final exponentiation in [2]. They prove that these new methods save an important number of temporary variables, and they are certainly faster than the existing one. In this paper, we will also present a new way of computing Miller loop, more precisely in the doubling algorithm. So we will use this result and the arithmetic optimization presented in [2]. Then, we will apply hardware optimization to find a satisfactory design which give the best compromise between area occupation and execution time. Our hardware implementation on a Virtex-6 FPGA(XC6VHX250T) used only 5976 Slices, 30 DSP, which is less resources used compared with state-ofthe-art hardware implementations, so we can say that our approach cope with the limited resources of restricted environmen

A high efficiency low noise rf-to-dc converter employing gm-boosting envelope detector and offset canceled latch comparator

This work presents a high efficiency RF-to-DC conversion circuit composed of an LC-CL balun-based Gm-boosting envelope detector, a low noise baseband amplifier, and an offset canceled latch comparator. It was designed to have high sensitivity with low power consumption for wakeup receiver (WuRx) applications. The proposed envelope detector is based on a fully integrated inductively degenerated common-source amplifier with a series gate inductor. The LC-CL balun circuit is merged with the core of the envelope detector by sharing the on-chip gate and source inductors. The proposed technique doubles the transconductance of the input transistor of the envelope detector without any extra power consumption because the gate and source voltage on the input transistor operates in a differential mode. This results in a higher RF-to-DC conversion gain. In order to improve the sensitivity of the wake-up radio, the DC offset of the latch comparator circuit is canceled by controlling the body bias voltage of a pair of differential input transistors through a binary-weighted current source cell. In addition, the hysteresis characteristic is implemented in order to avoid unstable operation by the large noise at the compared signal. The hysteresis window is programmable by changing the channel width of the latch transistor. The low noise baseband amplifier amplifies the output signal of the envelope detector and transfers it into the comparator circuit with low noise. For the 2.4 GHz WuRx, the proposed envelope detector with no external matching components shows the simulated conversion gain of about 16.79 V/V when the input power is around the sensitivity of −60 dBm, and this is 1.7 times higher than that of the conventional envelope detector with the same current and load. The proposed RF-to-DC conversion circuit (WuRx) achieves a sensitivity of about −65.4 dBm based on 45% to 55% duty, dissipating a power of 22 µW from a 1.2 V supply voltage. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1

Emerging embedded nonvolatile memory solution for ultra low power microcontroller systems

13301甲第4810号博士（工学）金沢大学博士論文本文Full 以下に掲載および掲載予定：1.IEEE Journal of Solid-State Circuits 27(4) pp.569-573 1992. IEEE. 共著者：M. Hayashikoshi, H. Hidaka, K. Arimoto, K. Fujishima 2.IEEE Transactions on Multi-Scale Computing Systems IEEE. 共著者：M. Hayashikoshi, H. Noda, H. Kawai, Y. Murai, S. Otani, K. Nii, Y. Matsuda, H. Kond

Inverse Kinematic Analysis of Robot Manipulators

An important part of industrial robot manipulators is to achieve desired position and orientation of end effector or tool so as to complete the pre-specified task. To achieve the above stated goal one should have the sound knowledge of inverse kinematic problem. The problem of getting inverse kinematic solution has been on the outline of various researchers and is deliberated as thorough researched and mature problem. There are many fields of applications of robot manipulators to execute the given tasks such as material handling, pick-n-place, planetary and undersea explorations, space manipulation, and hazardous field etc. Moreover, medical field robotics catches applications in rehabilitation and surgery that involve kinematic, dynamic and control operations. Therefore, industrial robot manipulators are required to have proper knowledge of its joint variables as well as understanding of kinematic parameters. The motion of the end effector or manipulator is controlled by their joint actuator and this produces the required motion in each joints. Therefore, the controller should always supply an accurate value of joint variables analogous to the end effector position. Even though industrial robots are in the advanced stage, some of the basic problems in kinematics are still unsolved and constitute an active focus for research. Among these unsolved problems, the direct kinematics problem for parallel mechanism and inverse kinematics for serial chains constitute a decent share of research domain. The forward kinematics of robot manipulator is simpler problem and it has unique or closed form solution. The forward kinematics can be given by the conversion of joint space to Cartesian space of the manipulator. On the other hand inverse kinematics can be determined by the conversion of Cartesian space to joint space. The inverse kinematic of the robot manipulator does not provide the closed form solution. Hence, industrial manipulator can achieve a desired task or end effector position in more than one configuration. Therefore, to achieve exact solution of the joint variables has been the main concern to the researchers. A brief introduction of industrial robot manipulators, evolution and classification is presented. The basic configurations of robot manipulator are demonstrated and their benefits and drawbacks are deliberated along with the applications. The difficulties to solve forward and inverse kinematics of robot manipulator are discussed and solution of inverse kinematic is introduced through conventional methods. In order to accomplish the desired objective of the work and attain the solution of inverse kinematic problem an efficient study of the existing tools and techniques has been done. A review of literature survey and various tools used to solve inverse kinematic problem on different aspects is discussed. The various approaches of inverse kinematic solution is categorized in four sections namely structural analysis of mechanism, conventional approaches, intelligence or soft computing approaches and optimization based approaches. A portion of important and more significant literatures are thoroughly discussed and brief investigation is made on conclusions and gaps with respect to the inverse kinematic solution of industrial robot manipulators. Based on the survey of tools and techniques used for the kinematic analysis the broad objective of the present research work is presented as; to carry out the kinematic analyses of different configurations of industrial robot manipulators. The mathematical modelling of selected robot manipulator using existing tools and techniques has to be made for the comparative study of proposed method. On the other hand, development of new algorithm and their mathematical modelling for the solution of inverse kinematic problem has to be made for the analysis of quality and efficiency of the obtained solutions. Therefore, the study of appropriate tools and techniques used for the solution of inverse kinematic problems and comparison with proposed method is considered. Moreover, recommendation of the appropriate method for the solution of inverse kinematic problem is presented in the work. Apart from the forward kinematic analysis, the inverse kinematic analysis is quite complex, due to its non-linear formulations and having multiple solutions. There is no unique solution for the inverse kinematics thus necessitating application of appropriate predictive models from the soft computing domain. Artificial neural network (ANN) can be gainfully used to yield the desired results. Therefore, in the present work several models of artificial neural network (ANN) are used for the solution of the inverse kinematic problem. This model of ANN does not rely on higher mathematical formulations and are adept to solve NP-hard, non-linear and higher degree of polynomial equations. Although intelligent approaches are not new in this field but some selected models of ANN and their hybridization has been presented for the comparative evaluation of inverse kinematic. The hybridization scheme of ANN and an investigation has been made on accuracies of adopted algorithms. On the other hand, any Optimization algorithms which are capable of solving various multimodal functions can be implemented to solve the inverse kinematic problem. To overcome the problem of conventional tool and intelligent based method the optimization based approach can be implemented. In general, the optimization based approaches are more stable and often converge to the global solution. The major problem of ANN based approaches are its slow convergence and often stuck in local optimum point. Therefore, in present work different optimization based approaches are considered. The formulation of the objective function and associated constrained are discussed thoroughly. The comparison of all adopted algorithms on the basis of number of solutions, mathematical operations and computational time has been presented. The thesis concludes the summary with contributions and scope of the future research work

A Techno-Economic Analysis of Space-Based Solar Power Systems

Space-based solar power (SBSP) promises to provide flexible renewable baseload power. However, no full-system prototype exists due to a perceived lack of economic viability. The goal of this thesis is therefore to determine how different technology approaches can improve key technical metrics of SBSP and consequently the economics. For this purpose, we divide the system into its three main segments and define critical metrics for the performance of each subsystem. Based on these, novel technology approaches from the literature are then evaluated. For the solar satellite, we are able to show that a number of technology options exist that might improve power levels, radiation resistance, and mass-related ratios. These advances would greatly benefit overall system economics, as the space segment constitutes a big lever for enhancing the levelised cost of electricity (LCOE). Furthermore, microwave power beaming efficiencies in line with required levels have been demonstrated but so far lack the scale and distance necessary for SBSP. Ultimately, the global capacity in space lift capabilities appears to be a major bottleneck. Consequently, a reduction in mass of the satellite would not only be a matter of economics but might render any such project even possible in the first place. Keywords: Energy; Solar; Space; Microwaves; Sustainability.Space-based solar power (SBSP) promises to provide flexible renewable baseload power. However, no full-system prototype exists due to a perceived lack of economic viability. The goal of this thesis is therefore to determine how different technology approaches can improve key technical metrics of SBSP and consequently the economics. For this purpose, we divide the system into its three main segments and define critical metrics for the performance of each subsystem. Based on these, novel technology approaches from the literature are then evaluated. For the solar satellite, we are able to show that a number of technology options exist that might improve power levels, radiation resistance, and mass-related ratios. These advances would greatly benefit overall system economics, as the space segment constitutes a big lever for enhancing the levelised cost of electricity (LCOE). Furthermore, microwave power beaming efficiencies in line with required levels have been demonstrated but so far lack the scale and distance necessary for SBSP. Ultimately, the global capacity in space lift capabilities appears to be a major bottleneck. Consequently, a reduction in mass of the satellite would not only be a matter of economics but might render any such project even possible in the first place. Keywords: Energy; Solar; Space; Microwaves; Sustainability