A Blockchain-Based Proxy Re-Encryption Scheme with Conditional Privacy Protection and Auditability

With the development of Internet of Things technology,intelligent door lock devices are widely used in the field of house leasing.In the traditional housing leasing scenario,problems of door lock information disclosure,tenant privacy disclosure and rental contract disputes frequently occur,and the security,fairness and auditability of the housing leasing transaction cannot be guaranteed.To solve the above problems,a blockchain-based proxy re-encryption scheme with conditional privacy protection and auditability is proposed.The scheme implements fine-grained access control of door lock data based on attribute encryption technology with policy hiding,and uses proxy re-encryption technology to achieve auditable supervision of door lock information transactions.Homomorphic encryption technology and zero-knowledge proof technology are introduced to ensure the confidentiality of housing rent information and the fairness of rent payment.To construct a decentralized housing lease transaction architecture,the scheme realizes the efficient collaboration between the door lock data ciphertext stored under the chain and the key information ciphertext on the chain based on the blockchain and InterPlanetary File System.Finally,the security proof and computing performance analysis of the proposed scheme are carried out.The results show that the scheme can resist the chosen plaintext attack and has low computational cost.

A Stackelberg Game for Spectrum Leasing in Cooperative Cognitive Radio Networks

According to the property-rights model of cognitive radio, primary users （PUs） who own the spectrum resource have the right to lease part of spectrum to secondary users （SUs） in exchange for appropriate profit. In this paper, we propose a pricing-based spectrum leasing framework between one PU and multiple SUs. In this scenario, the PU attempts to maximize its utility by setting the price of spectrum. Then, the selected SUs have the right to decide their power levels to help PU s transmission, aiming to obtain corresponding access time. The spectrum leasing problem can be cast into a stackelberg game, where the PU plays the seller-level game and the selected SUs play the buyer-level game. Through analysis based on the backward induction, we prove that there exists a unique equilibrium in the stackelberg game with certain constraints. Numerical results show that the proposed pricing-based spectrum leasing framework is effective, and the performance of both PU and SUs is improved, compared to the traditional mechanism without cooperation.

A Cost-Effective Cloud Leasing Policy for Live Streaming Applications

The dynamics of the globalized multimedia sources and request demands, which requires high computations and bandwidths, makes the IT infrastructure a challenge for live streaming applications. Migrating the system to a geo-distributed cloud and leasing servers is an ideal alternative for supporting large-scale live streaming applications with dynamic contents and demands. The new challenge of multimedia live streaming applications in a geo-distributed cloud is how to efficiently arrange and migrate services among different cloud sites to guarantee the distribute users’ experience at modest costs. This paper first investigates cloud leasing policies for live streaming applications and finds that there is no detailed algorithm to help live streaming applications arrange and migrate services among different cloud sites. Then, we present a quality of service（Qo S） guarantee cost-effective cloud leasing policy for live streaming applications. Meanwhile, we design a genetic algorithm（GA） to deal with the leasing policy among cloud sites of diverse lease prices. Experimental results confirm the effectiveness of the proposed model and the efficiency of the involved GA.

Novel pricing model for spectrum leasing in secondary spectrum market

According to the property rights model of cognitive radio,primary users who own the spectral resource have the right to lease or trade part of it to secondary users in exchange for appropriate profit.In this paper,an implementation of this framework is investigated,where a primary link can lease the owned spectrum to secondary nodes in exchange for cooperation （relaying）.A novel pricing model is proposed that enables the trading between spectrum and cooperation.Based on the demand of secondary nodes,the primary link attempts to maximize its quality of service （QoS） by setting the price of spectrum.Taking the price asked by primary link,the secondary nodes aim to obtain most profits by deciding the amount of spectrum to buy and then pay for it by cooperative transmission.The investigated model is conveniently cast in the framework of seller/buyer （Stackelberg） games.Analysis and numerical results show that our pricing model is effective and practical for spectrum leasing based on trading spectral resource for cooperation.

An Analysis of the Realty Leasing Market in Qianmen and Zhongguancun Areas of Beijing

The urban realty market is very complicated with wide-ranging contents and manyproblems. in the past, we focused our research mainly on the land auction, land rental inbatches, public bidding and the development of mass plots of land in the coastal open cit-ies, while neglecting the research on the real estate leasing and structural readjustment ofurban land use and housing Therefore. we have selected two typical areas in Beijing foron-the -spot investigation. One is Qianmen ——the most prosperous area in Beijingwith all kinds of big, medium-sized and small enterprises of public, collective and privateownership, and with brisk commercial activities and busy real estate leasing business. Theother area is the Zhongguancun ——the key section of the experimental area in Beijing forthe development of new technology and industries. In the past few years there have set upnew and high-tech enterprise groups with multiple subjects, Various categories and acombination of technology, industry and trade, which represent the direction for the de-velopment of science, technology and new productivity. Along with the mass explosivedevelopment of a large number of companies, the structure of the land use in that area haschanged dramatically. the leasing and transaction of the real estate are very active the re,and the rents and prices of land and housing have come up to the highest in Beijing.

Valuing options to renew at future market value:the case of commercial property leases

In this study,we develop and empirically test a valuation model for a commonly encountered option in office leases:a tenant’s option to renew at future market rent(a fair market value)with lease termination as the maturity date.The model integrates decision analysis with real options analysis and market risk with private risks.“Option value”is defined as the private value of the option to either party pre-contract,while“option price”assumes a fair agreement between transacting parties and can be positive(rental premium paid)or negative(rental discount offered).Without manifest expectations,an analysis of a sample of office leases supports the model’s logic with price estimates in a practical range.The tenants’option price/value is shown to have a negative relationship with the original/renewal lease term;conversely,the landlords’option value is positively related to the original/renewal term.Comparative analyses show that transaction costs have a positive effect on tenants’option value and on prices,while vacancy costs and the vacancy period are both positively related to the landlords’option value and negatively related to price.Market rent is found to have a negative relationship with option price.Overall,this study provides a theoretical analysis and empirical tests of the value of a real option that allows option holders to renew/extend their contracts at a fair market value.

美国租赁会计准则修订、影响及经验借鉴

IFRS16 Lease和US GAAP更新稿ASU2016-02 Lease(Topic842)(以下简称Topic842或新准则)先后于2016年1月和2月发布。通过回顾租赁准则的修订背景,比较Topic842与US GAAP ASC840后认为:(1)新准则的主要变化在于租赁定义、承租人租赁业务(除短期租赁外)表内确认及售后租回业务确认与计量等方面;(2)承租人融资租赁判断标准及会计处理理念、承租人经营租赁对综合收益表和现金流量表的影响未发生变化;(3)融资租赁出租人会计处理除与Topic606指引相协调发生变化外总体未变;(4)新准则能够有效增强信息透明度与可比性,但因Topic842依旧侧重区分租赁合同实质加以分类处理,故复杂程度高于IFR S16 Lease。

Effects of Labor Price Hike and Population Ageing on Rural Land Lease in China

In answering the questions as whether China's rising labor price and ageing workforce have affected rural land leasing and whether these factors have any joint effect,we have employed RCRE data of the Ministry of Agriculture to carry out an empirical analysis and the result indicates that labor price hike has significant positive effects on both the land lease-in and lease-out of rural households,i.e.labor price hike will help increase the land leasing of rural households.At the level of ageing workforce,our empirical results indicate that ageing workforce does not create any significant impact on rural land leasing market no matter for land lease-in or lease-out in overall samples,plain regions and mountainous regions.In our empirical analysis on whether ageing workforce will intensify or weaken the effects of labor price hike on rural land leasing market,the regression result also indicates that there is no significant effect from a statistical perspective.

一种新的变步长LMS算法

为了提高LMS自适应算法的性能,在对传统LMS算法、变步长LMS算法及其改进算法分析的基础上,提出了一种新的步长与误差信号之间的函数关系。既能保证均方误差收敛、有较小的失凋,又能在算法达到稳态时,在低信噪比环境下有很好的跟踪性能,并且不易受噪声影响。理论分析和计算机仿真结果均表明该算法优于传统算法。

租赁业的基本分类及概念辨析

本文对国内外关于租赁业的几个基本分类及概念进行了梳理和分析,说明了相关概念的区别与联系。

Contingent convertible lease modeling and credit risk management

The main objective of this study is to determine a lease agreement to finance an investment project and a solution for managing credit risk.This study investigates three types of contingent leases to reduce the costs associated with bankruptcy and compensate for the lessor’s position.A leasing defaultable contract allows the lessor to obtain the rent that will be recovered if the lessee defaults.A leasing convertible contract can be automatically converted into shares when certain default conditions related to the cash flows generated by the firm are met.These conditions are triggered by the ratio of the firm’s value and leasing payments.A Defaultable-Convertible-Leasing contract with a payback option grants the lessor the right but not the obligation to convert the remaining lease payments into stocks or to break up the contract and pick up the rented equipment when the firm reaches the default threshold.These contracts are motivated by contributing to the range of risk-management strategies by adding more flexibility to standard leasing contracts and contingent rents.Closed-form securities pricing solutions are set forward in a dynamic model for firms with existing assets and a growth option financed by shares and a contingent lease.Risk-neutral pricing theory and the backward induction method are used to determine the pricing of corporate securities.Numerical analysis shows that leasing convertible contracts and defaultable-convertible contracts with payback options impact the service value of the leased asset,maturity,and inefficiencies resulting from insolvency and asset substitution.An optimal conversion rate reduces inefficiencies,thus making the leasing convertible contract and defaultable-convertible-leasing contract with payback option a reliable solution to ensure business continuity and loss coverage of the leasers upon default.

Laws,Defects and Countermeasures on the Circulation of Rural Housing Land——From the Perspective of Farmer Rights Protection

The thesis combs the existing legal provisions about rural housing land from the perspectives of use restriction,means restriction,subject restriction and mortgage prohibition,and finds out their defects,namely,weakening real right,confused knowledge about the integration of house property and land property,the loophole in Land Administration Law,the bans on the rural residents' purchase of housing land and so on.Then the thesis expounds the harms of restricting the circulation of housing land,for example,it will result in underground transaction of housing lands;lead to untenanted lands and waste of resources;bring about financing difficulty for peasants;do harm to the interest of land owners(rural collective economic organizations) and so on.The thesis further proposes to establish the legal lease model to solve the problems in the circulation of housing lands,specifically explains the definition of the legal lease model of housing lands,illustrates its detailed information from the aspects of object,subject and content and elaborates a series of problems involving,how to distribute the rent of housing lands,as well as how to perfect relevant procedures and formalities in the credit circulation of housing lands so as to realize the legitimate and effective circulation of rural housing lands and protect the peasants' interests.

Web强缓存一致性的研究

Web对象缓存技术是一种减少web服务器访问通信量和访问延迟的重要手段。Web缓存的引入虽然大大减轻了服务器负载,降低了网络拥塞,减少了客户端访问的延迟等优点,但同时也带来缓存的一致性问题,这样使客户端获得web的数据可能不是最新的版本。该文通过分析现有的缓存一致性方针,提出了一个应适于web的强缓存一致性算法。

THEORETICAL AND EXPERIMENTAL RESULTS ON THE KINETICS OF CALCITE DISSOLUTION AND PRECIPITATION

INTRODUCTION Dissolution and precipitation of carbonates plays an important role in nature, such as in the chemistry of seawater, the sedimentation of carbonate at the seafloor, the geochemical evolution of freshwater aquifers and last but not least, most spectacular, the evolution of karst landscapes. To provide a deeper understanding to all these processes knowledge is required

WORLD NEWS IN BRIEF (September 16-30, 1991)

The Philippines senate rejected a new lease for the Subic Pay naval base on Septemker 16 in a vote that could end America’s 93-year military presence in the Philippines. The senate voted 12-11 on second reading to reject the friendship treaty between the two countries signed last month.

The Profit Model of Long-Term Lease Apartments Under Multi-Agent Supply

The acceleration of urbanization has led to an increase in the number of urban floating population, which leads to more demands for the housing rental market. With the support of policies, long-term lease apartments have begun to emerge. However, under the multi-subject supply, longterm lease apartments have encountered problems such as small profits in their development. Starting from the background of the development of long-term lease apartments, this study classified the main types of long-term lease apartments, analyzed the four profit models of comprehensive profit, expansion of rent difference, REITs and value-added services based on their business models, and proposed corresponding suggestions on the profitability of long-term lease apartments according to the current situation of profit difficulty of long-term lease apartments and the lack of profit models.

Relevance in the Application of IFRS 16 for Financial Statements:Empirical Evidence the Impact of the Financial Method in SMEs

Leasing is confirmed among the preferred forms of financing by SMEs(Small and Medium Enterprises),even if its use grows both among large companies and private individuals.The stipulated in Europe increased in 2017 by 8.3%over the previous year.From 1 January 2019 the new accounting standard IFRS 16 is in force,which concerns the accounting of leasing contracts.The new methods of accounting for leasing contracts in the financial statements drawn up based on international accounting standards come into force.In fact,as from 1 January 2019,the IAS adopters are required to apply the new IFRS 16 standard,introduced in place of IAS 17,with the aim of standardizing the methods for recognizing leasing contracts in the financial statements.Scientifically,the most important researches concerning leasing have dealt with the topic focusing on accounting harmonization,accounting for leasing,capitalization of leasing and tax.Through the theoretical analysis and the simulation of our case study we want to answer a question:How the change in the accounting of leases is reflected in the financial statements?

The Spatial Organization Dialectics of the City ofJeriquara/SP, Brazil

The present paper aims to analyze and discuss the morphological formation of the city of Jeriquara, located in the countryside of the state of S o Paulo, Brazil. The importance of this study lays on its primary documentation, that is, the long lease deeds (cartas de aforamento). These deeds are part of the medieval legal system implemented in Brazil by the Portuguese. The long lease, perpetual lease or tenure, or fiefdom (in the Brazilian legal system, aforamento, enfiteuse or emprazamento) are synonyms of this legal institute that divides urban land between two holders: the Catholic Church and the civil individual. This article employs as research method the interpretive and descriptive analysis of such deeds, based on theoretical bibliography on the referred legal institute, civil law and the Brazilian forms of urbanization. Following the presentation of a case study there will be the discussion of the juridical issues at the core of the national colonization implemented by the Portuguese and which are at the genesis of several of the current conflicts. This study shows that the urban territory of many cities is still ruled by these past contexts and, without understanding them, we will not be able to efficiently interfere with city spaces.

Research on Influencing Factors of Residential Rental Price Based on Hedonic Price Model:A Case Study of Nanshan District,Shenzhen

Taking Nanshan District,Shenzhen as an example,the paper studies the influencing factors of residential rental price via hedonic price model.The hedonic price index system is constructed and relevant characteristic variables are selected from the perspectives of building characteristics,location characteristics,neighborhood characteristics and rental characteristics.The residential rental data in the second half of 2020 are analyzed by multi-factors linear regression,and hedonic price model of house lease in Nanshan District is obtained to analyze the inherent law of residential rental price structure in this area.

略谈英语中“开”的表达法

有汉语中,“开”的意义异常丰富,是个多义词。与其相对应,英语中也就有各种不同的表达方式,略举例如下: 1.门开了,这时向老师走了进来。 The door was opened when Mr Xiang came in. 2.他们下周星期三将开会。