投资组合的构建过程是由下述步骤组成:
首先,需要界定适合于选择的证券范围。对于大多数计划投资者其注意的焦点集中在普通股票、债券和货币市场工具这些主要资产类型上。这些投资者已经把诸如国际股票、非美元债券也列入了备选的资产类型,使得投资具有全球性质。有些投资者把房地产和风险资本也吸纳进去,进一步拓宽投资的范围。虽然资产类型的数目仍是有限的,但每一资产类型中的证券数目可能是相当巨大的。
其次,投资者还需要求出各个证券和资产类型的潜在回报率的期望值及其承担的风险。此外,更重要的是要对这种估计予以明确地说明,以便比较众多的证券以及资产类型之间哪些更具吸引力。进行投资所形成投资组合的价值很大程度上取决于这些所选证券的质量。
构建过程的第三阶段,即实际的最优化,必须包括各种证券的选择和投资组合内各证券权重的确定。在把各种证券集合到一起形成所要求的组合的过程中,不仅有必要考虑每一证券的风险-回报率特性,而且还要估计到这些证券随着时间的推移可能产生的相互作用。马考维茨模型用客观和修炼的方式为确定最优投资组合提供了概念性框架和分析方法。
② 投资组合管理的构成
投资组合管理由以下三类主要活动构成:
(1)资产配置
(2)在主要资产类型间调整权重
(3)在各资产类型内选择证券。
资产配置的特征是把各种主要资产类型混合在一起,以便在风险最低的条件下,使投资获得最高的长期回报。投资组合管理者以长期投资目标为出发点,为提高回报率时常审时度势改变各主要资产类别的权重。例如,若一个经理判断在未来年份内权益的总体状况要比债券的总体状况对投资者更加有利的话,则极可能要求把投资组合的权重由债券向权益转移,而且,在同一资产类型中选择那些回报率高于平均回报率的证券,经理便能改善投资组合回报的前景。
投资组合的构建就是选择纳入投资组合的证券并确定其适当的权重,即各证券所占该投资组合的比例。马考维茨(Markowitz)模型表明,构建投资组合的合理目标应是在给定的风险水平下形成一个具有最高回报率的投资组合。具有这种特征的投资组合叫做有效的投资组合,它已经被广泛地接受为最优投资组合构建的典范。
此外,马考维茨模型还为构建能实现最有效这一目标的投资组合提供了一种明确的和修炼的过程(这种过程被称为最优化),这种最优化过程已经被广泛地应用于大型计划的投资者确定投资组合中各主要资产类型的最佳组合的活动中。这种过程通常被称做资产配置(assetallocation),因为实际中可考虑的主要资产类型是有限的,所以它是可操作的。当考虑的证券总体数目超过某一限制时,马考维茨最优化过程是难以实践的,因此就需要采用将在下两章讨论的其他替代方法。
由于马考维茨模型提出了有效投资组合构建中的基本概念,也为投资组合分析的其他方面奠定了基础。其中将涉及有效的投资组合和多样化的概念,这些概念是构建投资组合的基础。
③ 投资组合管理是什么
投资组合管理是指投资管理人按照资产选择理论与投资组合理论对资产进行多元化管理,以实现分散风险、提高效率的投资目的。
④ ACCA,CISA,FSA,CFA,CFP,PMP谁帮忙用英文解释下这几个金融资格职业证书,(不要解释是什么的缩写)
CISA is an audit professional certification sponsored by the Information Systems Audit and Control Association (ISACA). Candidates for the certification must meet requirements set by ISACA。
The CISA certification was established in 1978[1] for several reasons:
Develop and maintain a tool that could be used to evaluate an indivials' competency in concting information system audits.
Provide a motivational tool for information systems auditors to maintain their skills, and monitor the success of the maintenance programs.
Provide criteria to help aid management in the selection of personnel and development.
The first CISA examination was administered in 1981, and registration numbers have grown each year. Over 60,000[1] candidates have earned the CISA designation.
The CISA certification has been recognised with ANSI accreditation, along with the CISM certification- both of these certifications are managed by ISACA. It is one of the few certifications formally approved by the US Department of Defense in their Information Assurance Technical category (DoD 8570.01-M).
Requirements
Candidates for a CISA certification must pass the examination, agree to adhere to ISACA's Code of Professional Ethics, submit evidence of a minimum of five years of professional IS auditing, control, or security work, and abide by a program of continuing professional ecation.
Substitutions and waivers of such experience may be obtained as follows:[2]
A maximum of one year of information systems experience OR one year of financial or operational auditing experience can be substituted for one year of information systems auditing, control, or security experience.
60 to 120 completed college semester credit hours (the equivalent of an Associate or Bachelor degree) can be substituted for one or two years, respectively, of information systems auditing, control or security experience.
Two years as a full-time university instructor in a related field (e.g., computer science, accounting, information systems auditing) can be substituted for one year of information systems auditing, control or security experience.
[edit] Examination
The exam consists of 200 multiple-choice questions that must be answered within 4 hours. The exam is split between 6 Content Areas as of 2006:
IS Audit Process - 10% of Exam
IT Governance - 15% of Exam
Systems and Infrastructure Lifecycle Management - 16% of Exam
IT Service Delivery and Support - 14% of Exam
Protection of Information Assets - 31% of Exam
Business Continuity and Disaster Recovery - 14% of Exam
The exam is now offered in 11 languages at more than 200 locations worldwide in June and December.
The Association of Chartered Certified Accountants (ACCA) is a British chartered accountancy body with a global presence that offers the Chartered Certified Accountant (Designatory letters ACCA or FCCA) qualification worldwide. It is one of the world's largest and fastest-growing accountancy bodies with 122,426 members and 325,606 affiliates and students in 170 countries. The Institute's headquarters are in London with the principal administrative office being based in Glasgow. In addition the ACCA has a network of nearly 80 staffed offices and other centres around the world.
The ACCA is a founding member body of the Consultative Committee of Accountancy Bodies (CCAB) and the International Federation of Accountants (IFAC).
The term 'Chartered' in ACCA qualification refers to the Royal Charter granted in 1974 by Her Majesty the Queen in the United Kingdom.
Since Chartered Certified Accountant is a legally protected term, indivials who describe themselves as Chartered Certified Accountants must be members of ACCA and, if they carry out public practice engagements, must comply with additional regulations such as holding a practising certificate, being insured against any possible liability claims and submitting to inspections.
The Association of Authorised Public Accountants (AAPA), one of the British professional bodies for public accountants, has been a subsidiary of ACCA since 1996.
FSA is an independent non-governmental body, quasi-judicial body and a company limited by guarantee that regulates the financial services instry in the United Kingdom.
The Financial Services and Markets Act imposed four statutory objectives upon the FSA:
market confidence: maintaining confidence in the financial system
public awareness: promoting public understanding of the financial system;
consumer protection: securing the appropriate degree of protection for consumers; and
rection of financial crime: recing the extent to which it is possible for a business carried on by a regulated person to be used for a purpose connected with financial crime
[edit] Regulatory principles
The statutory objectives are supported by a set of principles of good regulation which the FSA must have regard to when discharging its functions. These are:
efficiency and economy: the need to use its resources in the most efficient and economic way.
role of management: a firm’s senior management is responsible for its activities and for ensuring that its business complies with regulatory requirements. This principle is designed to guard against unnecessary intrusion by the FSA into firms’ business and requires it to hold senior management responsible for risk management and controls within firms. Accordingly, firms must take reasonable care to make it clear who has what responsibility and to ensure that the affairs of the firm can be adequately monitored and controlled.
proportionality: The restrictions the FSA imposes on the instry must be proportionate to the benefits that are expected to result from those restrictions. In making judgements in this area, the FSA takes into account the costs to firms and consumers. One of the main techniques they use is cost benefit analysis of proposed regulatory requirements. This approach is shown, in particular, in the different regulatory requirements applied to wholesale and retail markets.
innovation: The desirability of facilitating innovation in connection with regulated activities. For example, allowing scope for different means of compliance so as not to unly restrict market participants from launching new financial procts and services.
international character: Including the desirability of maintaining the competitive position of the UK. The FSA takes into account the international aspects of much financial business and the competitive position of the UK. This involves co-operating with overseas regulators, both to agree international standards and to monitor global firms and markets effectively.
competition: The need to minimise the adverse effects on competition that may arise from the FSA's activities and the desirability of facilitating competition between the firms it regulates. This covers avoiding unnecessary regulatory barriers to entry or business expansion. Competition and innovation considerations play a key role in the FSA's cost-benefit analysis work. Under the Financial Services and Markets Act, the Treasury, the Office of Fair Trading and the Competition Commission all have a role to play in reviewing the impact of the FSA's rules and practices on competition.
[edit] Accountability and management
The FSA is accountable to Treasury Ministers, and through them to Parliament. It is operationally independent of Government and is funded entirely by the firms it regulates through fines, fees and compulsory levies. Its Board consists of a Chairman, a Chief Executive Officer, a Chief Operating Officer, two Managing Directors, and 11 non-executive directors (including a lead non-executive member, the Deputy Chairman) selected by, and subject to removal by, HM Treasury. Among these, the Deputy Governor for Financial Stability of the Bank of England is an ex officio Board member. This Board decides on overall policy with day-to-day decisions and management of the staff being the responsibility of the Executive. This is divided into three sections each headed by a Managing director and having responsibility for one of the following sectors: retail markets, wholesale and institutional markets, and regulatory services.
Its regulatory decisions can be appealed to the Financial Services and Markets Tribunal.
HM Treasury decides upon the scope of activities that should be regulated, but it is for the FSA to decide what shape the regulatory regime should take in relation to any particular activities.
The FSA is also provided with advice on the interests and concerns of consumers by the Financial Services Consumer Panel [2]. This panel describes itself as "An Independent Voice for Consumers of Financial Services". Members of the panel are appointed and can be dismissed by the FSA and emails to them are directed to FSA staff. The Financial Services Consumer Panel will not address indivial consumer complaints.
Chartered Financial Analyst (CFA) is an international professional designation offered by the CFA Institute of USA (formerly known as AIMR) to financial analysts who complete a series of three examinations. Candidates must have a bachelor's degree (or equivalent), be in the final year of their bachelor's degree program, or have at least four years of qualified, professional work experience in order to take the exams. In order to become a "CFA Charterholder" candidates must pass all three exams, agree to comply with the code of ethics, pay member es, and have four years of work experience deemed acceptable by the CFA Institute. CFA charterholders are also obligated to adhere to a strict Code of Ethics and Standards governing their professional conct
The Certified Financial Planner (CFP) designation is a certification mark for financial planners conferred by the Certified Financial Planner Board of Standards in the United States, Financial Planners Standards Council in Canada and 18 other organizations affiliated with Financial Planning Standards Board (FPSB), the international owner of the CFP mark outside of the United States. To receive authorization to use the designation, the candidate must meet ecation, examination, experience and ethics requirements, and pay an ongoing certification fee.[1]. The information contained herein relates specifically to CFP certification in the United States. For information on CFP certification outside of the United States, please see the FPSB website at http://www.fpsb.org/CMS/index.php?option=com_content&task=view&id=84&Itemid=110 for a list of affiliate member organizations and their respective websites.
The CFP Certification Examination is a 10-hour multiple choice exam, divided into one four-hour session (Friday afternoon) and two three-hour sessions (Saturday). The exam includes three major case problems and is designed to assess the student's ability to apply his or her knowledge of the aforementioned areas to financial planning situations. The exam was set as a requirement in 1993 and at that time CFPs were grandfathered without having to pass this exam. [5]
Indivials holding professional designations pre-approved by the CFP Board (like PhDs in business and economics, attorneys, Certified Public Accountants (CPA), Chartered Certified Accountants (ACCA), Chartered Accountants (CA), Chartered Wealth Managers (AAFM) ), and Chartered Financial Analysts (CFA) are entitled to register for and take the exam without having to complete the ecation requirements by using the CFP-board's challenge status.
Project Management Professional is properly expressed as the credential PMP. The credentialing agency is the Project Management Institute ([1] PMI). This credential is obtained by gaining a certification in project management through the completion of PMI certified training and examination. PMP training and examination material comes from the Guide to the Project Management Body of Knowledge PMBOK published most recently in 2007. Most exam questions reference PMI's project quality standards documented in the PMBOK. The PMP credential undergoes rigorous validation by ISO, and the PMBOK methodology is widely regarded as the instry standard for Project Management and has been adopted as the single standard for project management by agencies such as NASA.
PMP (Project Management Professional) is one of four concentrations offered by PMI in the study of Project Management:
1. CAPM Certified Associate in Project Management: This certification is obtained after passing the CAPM Exam
2. PMP Project Management Professional: This certification is obtained after passing the PMP Exam
3. PgMP Program Management Professional: This certification is obtained after passing the PgMP Exam
4. PMI RMP PMI Risk Management Professional: This certification is obtained after passing the PMI-RMP Exam
⑤ 怎样进行基金资产投资组合管理
做好资产投资组合,一般需要考虑两点:
第一是个人或者家庭的风险偏好,不同的风险偏好,决定了你适合投资不同的资产。
第二是理财目标,理财目标有长有短,投资的金额也不一样,投资的资产也不一样。
至于怎么做,如果自己有兴趣的话,可以多学习;如果不想学习,也可以找个理财师帮助你。
⑥ 证券投资组合理论的基本内容是什么
证券组合收益率、证券组合风险、双证券组合风险、系统性风险。
投资组合理论有狭义和广义之分。狭义的投资组合理论指的是马柯维茨投资组合理论;而广义的投资组合理论除了经典的投资组合理论以及该理论的各种替代投资组合理论外,还包括由资本资产定价模型和证券市场有效理论构成的资本市场理论。同时,由于传统的EMH不能解释市场异常现象,在投资组合理论又受到行为金融理论的挑战。
⑦ 投资组合管理的要求
管理投资组合是一个持续的过程,同时涵盖了对静态资产和动态资产(比如项目等)的管理。在实际运行过程中,管理投资组合真正的难点在于它需要时刻保持高度的商业敏感,不断地进行分析和检讨,考察不断出现的新生机会、现有资产的表现以及企业为了利用现有机遇而进行的资源配置活动等等。
在瞬息万变的现实环境中,那些影响投资组合的资产和项目的价值往往都处在一个随时变化波动的状态之下,造成这种波动的原因可能是来自外部的影响因素:包括市场地位变化或者公司本身竞争地位的变化;同样,这种波动也可能是归因于内部的某些力量(比如:公司战略、产品组合、分销渠道的调整或者诸如成本和质量等竞争基础发生变化)。 投资组合的组件必须多样化而且要被控制在企业能够承受的风险范围之内。投资组合组件可以按照产出或者风险划分为几个等级。风险因素需要和达到预期收益的可能性、稳定性、技术风险等结合起来考虑。组件的风险等级决定了对其管理的紧密程度——包括审查的频繁程度以及资本更新的模式。
现有资产的投资组合需要从上文提及的各个角度进行管理,这些都是静态的,所以,我们还有必要从一种互动的角度出发来进行管理,也就是说还要仔细考查这些组件之间如何互动,组件和企业如何互动。
⑧ 求保险投资的英文论文和中文翻译
保险投资管理研究/Insurance Investment Management
中文关键词 保险投资 投资方式选择 投资阶段选择 投资风险控制
英文关键词 insurance investment choice of investment mold choice of investment stages investment risk control
摘要随着保险市场竞争的日趋加剧,投资收益已经成为保险公司最为主要的利润来源,是保险公司偿付能力额度增强的重要手段、是保险险种产品创新的重要推动力量、是提高保险企业竞争优势的关键举措。因此,对保险投资管理研究极具重要性。从国际资本市场发展情况看,在资本市场的发展与完善以及资本市场和保险投资管制的放松因素驱动的推动下,美国、日本的保险投资得到了大力的发展。发达国家保险投主体模式组建主要有三种,其一是,公司内设投资机构运作模式;其二是,委托专业的投资机构运作模式;其三是,投资管理公司运作模式。 从我国的具体发展情况看,我国保险投资起始于1984年。20世纪90年代,由于保险市场的主体的增加,竞争的加剧,保险投资的现状得到了一定的改善。进入新世纪后,我国保险投资开始逐步取得较好的成绩。当前我国现有保险投资工具主要有:银行存款;债券,主要包括国库券、金融债券、企业债券;以及证券投资基金。当前,我国保险投资存在的主要问题是:第一,保险投资过分依赖于银行存款、债券,加剧寿险公司的利率风险;第二,保险投资限制过多使保险费率居高不下,不仅增加被保险人的负担,而且容易导致保险人的费率恶性竞争;第三,保险投资的限制影响了保险投资组合管理策略的实施;第四,保险投资的限制在一定程度上制约了我国保险监管方式由静态监管向动态监管发展;第五,保险投资限制和资本市场的缺陷严重阻碍了保险投资资产负债管理方式的运用。因此,我国保险投资管理的重点是加强对保险投资方式选择和相关的策略研究。在保险投资方式上,要根据我国的具体国情、保险历史、法律环境情况,充分考虑本国经济发展的现实,不能盲目地与发达国家接轨。此外,根据我国资本市场和保险市场的现状,保险投资渠道必须积极稳妥的扩大,保险投资必须有步骤分阶段地进行。在不同阶段应该实施不同的保险投资重点。具体说来,保险投资第一阶段的重点是,加大金融债券的投资力度,扩大企业债券的投资比例;投资于稳定的基础设施参与住房金融业;从事住房抵押贷款;开展保单质押贷款业务。保险投资第二阶段的重点要转移是,提高证券投资基金的投资比例、设立证券投资保险基金或资产管理公司、保险资金直接入市保险资金投资于不动产。保险投资第三阶段重点则要定位为,保险投资与国际接轨,实现投资的国际化。此外,保险投资管理还必须加强风险管理的策略研究,一方面,要加强对保险公司投资风险的宏观监管,要建立现金流量测试模型,公司现金流量测试要由各保险公司的精算师独立完成,对财务比率分析、风险资本要求等指标进行静态监管。另一方面,要加强保险公司对投资风险的管理。保险公司加强保险投资主体模式建设,防范保险投资风险;保险公司应该以内控机制为基础,加强投资风险的防范;保险公司应该将投资管理从传统的财务管理中分离出来,实行专业化的基金管理;灵活运用现代证券投资组合理论,充分发挥投资组合分散投资风险的功能。
Abstract In company with more and more cutthroat competition in insurance market, investment yield became the uppermost source of profits, promoted as the important measure for solvency, acted as the force power of proct innovation, played as the key for improving the enterprise’s competitive edge. Thereby, investment management of insurance is very important work. In term of international capital market, America and Japan have made a great progress in investment management of insurance under a boost in perfect capital market and relaxing the control of investment management of insurance. The mode of investment in western countries had three patterns: section of a enterprise which contain the investment organization; entrusting the professional organization; investment administration organization. In term of national capital market, China first went about investment management of insurance in 1984. The situation of investment management of insurance improved e to the increasing insurance market subject and the intensifying competition from 1990’s. Nowadays, the development of investment management of insurance getting better and better progressively. The object of insurance investment involved the bank deposit and bond, which including treasury bill, financial bond, corporate bond and security investment fund. The insurance investment in china concerned with the following problems for the present. First, the insurance investment overly dependent upon the bank deposit and bond, which led to increasing interest rate risk of life insurance corporation. Second, the insurance investment overly regulated the rate of premium, which give rise to high rate of premium, piling the pressure on insurants and concting the cut throat competition among the insurers. Third, the regulation on the insurance investment affected executing the stratagem of portfolio management. Fourth, the regulation on the insurance investment restricted the mold of supervise developing dynamically. Fifth, the regulation on the insurance investment and the imperfect market restricted the mold of the assets and liabilities operation. The key of managing the insurance investment is how to selecting the mold of investment and correlated strategies. In aspect of the mold of investment, we should select the strategies which approached to inhabitant. According to our capital market and insurance market status, the insurance investment should widen the channel step by step. First, the investment section of financial bond and corporate bond should increase. Second, the investment section of security investment fund should increase. Third, the insurance investment should make international. Moreover, the insurance investment should pay attention to risk management, which including macro-supervise and micro-supervise.
什么是保险投资
保险投资指保险企业在组织经济补偿过程中,将积聚的各种保险资金加以运用,使资金增值的活动。
保险企业可运用的保险资金是由资本金、各项准备金和其他可积聚的资金组成。运用暂时闲置的大量准备金是保险资金运动的重要一环。投资能增加收入、增强赔付能力,使保险资金进入良性循环。
[编辑]保险投资的原则
保险投资原则是保险投资的依据。早在1862年,英国经济学家贝利(A.A.Bailey)就提出了寿险业投资的五大原则,即:安全性;最高的实际收益率;部分资金投资于能迅速变现的证券;另一部分资金可投资于不能迅速变现的证券;投资应有利于寿险事业的发展。
随着资本主义经济发展,金融工具的多样化,以及保险业竞争的加剧,保险投资面临的风险性、收益性也同时提高,投资方式的选择范围更加广阔。1948年英国精算师佩格勒(J.B.Pegler)修正贝利的观点,提出寿险投资的四大原则:获得最高预期收益;投资应尽量分散;投资结构多样化;投资应将经济效益和社会效益并重。
理论界一般认为保险投资有三大原则:安全性;收益性;流动性。
1、安全性原则
保险企业可运用的资金,除资本金外,主要是各种保险准备金,它们是资产负债表上的负债项目,是保险信用的承担者。因此,保险投资应以安全为第一条件。安全性,意味着资金能如期收回,利润或利息能如数收回。为保证资金运用的安全,必须选择安全性较高的项目。为减少风险,要分散投资。
2、收益性原则
保险投资的目的,是为了提高自身的经济效益,使投资收入成为保险企业收入的重要来源,增强赔付能力,降低费率和扩大业务。但在投资中,收益与风险是同增的,收益率高,风险也大,这就要求保险投资,把风险限制在一定程度内,实现收益最大化。
3、流动性原则
保险资金用于赔偿给付,受偶然规律支配。因此,要求保险投资在不损失价值的前提下,能把资产立即变为现金,支付赔款或给付保险金。保险投资要设计多种方式,寻求多种渠道,按适当比例投资,从量的方面加以限制。要按不同险种特点,选择方向。如人寿保险一般是长期合同,保险金额给付也较固定,流动性要求可低一些。国外人寿保险资金投资的相当部分是长期的不动产抵押贷款。财产险和责任险,一般是短期的,理赔迅速,赔付率变动大,应特别强调流动性原则。国外财产和责任保险资金投资的相当部分是商业票据、短期债券等。
在我国,保险公司的资金运用必须稳健,遵循安全性原则,并保证资产的保值增值。
[编辑]保险投资的形式
保险投资的形式是保险公司保险资金投放在哪些具体项目上。合理的投资形式,一方面可以保持保险企业财务稳定性和赔付的可靠性、及时性;另一方面可以避免资金的过份集中从而影响产业结构的合理性。
一般而言,保险资金可以投资于:
1、有价证券
有价证券主要有二种:
1)债券。包括政府债券、公司债券和金融债券等。一般地说,投资债券风险较小,尤其是政府债券。投资公司债券时,要特别注重该公司的资信和收益的可靠性。
2)股票。投资股票是有风险的,如果企业经营不善,效益不好,预期利息减少,以及影响股市的其他因素不佳,股票就会跌价。在国外对保险企业投资股票都有多种限制,如日本政府保险业法中规定购买股票不得超过总资产的30%。
2、抵押贷款
抵押贷款是指期限较长又较稳定的业务,特别适合寿险资金的长期运用。世界各国保险企业对住宅楼实行长期抵押贷款,大都采用分期偿还、本金递减的方式,收益较好。
3、寿险保单贷款
寿险保单具有现金价值。保险合同规定,保单持有人可以本人保单抵押向保险企业申请贷款,但需负担利息,这种贷款属保险投资性质。保单贷款金额限于保单当时的价值,贷款人不用偿贷款,保单会失效,保险企业无需给付保险金。
实际上,在这种贷款中保险人不担任何风险。在寿险发达国家,此项业务十分普遍。
4、不动产投资
不动产投资是指保险资金用于购买土地、房屋等不动产。此项投资的变现性较差,故只能限制在一定的比例之内。日本对保险企业购买不动产,规定不得超过其总资产的10%。
5、向为保险配套服务的企业投资
比如为保险汽车提供修理服务的汽车修理厂;为保险事故赔偿服务的公证行或查勘公司等。这些企业与保险事业相关,把保险资金投向于这些企业,有利于保险事业的发展。
在我国,保险公司的资金运用,限于银行存款、买卖政府债券、金融债券和国务院规定的其他资金运用等形式。并且特别明确规定,保险公司的资金不得用于设立证券经营机构和向企业投资。
⑨ 投资组合管理是风险转移么
是的,利用组合对冲非系统性风险。分散分风险。
⑩ 投资组合管理(投资学)的几个计算题,求帮忙做一下,要有过程
然后下楼给我买两瓶二锅头,买点芥末油。