Monday, January 18, 2016

COM Fundamentals

COM requires that the only way to gain access to the methods of an interface is through a pointer to the interface. An interface definition specifies the interface's member functions, called methods, their return types, the number and types of their parameters, and what they must do. There is no implementation associated with an interface. COM interfaces are immutable—You cannot define a new version of an old interface and give it the same identifier. Adding or removing methods of an interface or changing semantics creates a new interface, not a new version of an old interface. Therefore, a new interface cannot conflict with an old interface. However, objects can support multiple interfaces simultaneously and can expose interfaces that are successive revisions of an interface, with different identifiers. Thus, each interface is a separate contract, and systemwide objects need not be concerned about whether the version of the interface they are calling is the one they expect. The interface ID (IID) defines the interface contract explicitly and uniquely. All COM objects must implement the IUnknown interface。 For any given object instance, a call to QueryInterface(IID_IUnknown, ...) must always return the same physical pointer value(((IUnknown*)*ppv)->AddRef(); ). This allows you to call QueryInterface(IID_IUnknown, ...) on any two interfaces and compare the results to determine whether they point to the same instance of an object. Containment/Delegation(包容/托管) the outer object explicitly delegates implementation to the inner object's methods，That is, the outer object uses the inner object's services to implement itself.显然所有com对象都支持包容。 Aggregation is actually a specialized case of containment/delegation.the outer object exposes interfaces from the inner object as if they were implemented on the outer object itself. The following rules apply to creating an aggregable object: The aggregable (or inner) object's implementation of QueryInterface, AddRef, and Release for its IUnknown interface controls the inner object's reference count, and this implementation must not delegate to the outer object's unknown (the controlling IUnknown). The aggregable (or inner) object's implementation of QueryInterface, AddRef, and Release for its other interfaces must delegate to the controlling IUnknown and must not directly affect the inner object's reference count. The inner IUnknown must implement QueryInterface only for the inner object. The aggregable object must not call AddRef when holding a reference to the controlling IUnknown pointer. When the object is created, if any interface other than IUnknown is requested, the creation must fail with E_NOINTERFACE.

Friday, January 1, 2016

月记

Sunday, November 29, 2015

在温哥华办理美国签证攻略

非移民签证常见类型

CNMI-only(仅限于美国北玛利安纳群岛) transitional worker(CW-1).
business visitor商务访问(B-1)
Exchange visitor交换访问(J)
Intra-company transferee公司内部穿梭(L)
Tourism, vacation, pleasure visitor旅游(B-2)

照片场景要求

Sized such that the head is between 1 inch and 1 3/8 inches (22 mm and 35 mm) or 50% and 69% of the image's total height from the bottom of the chin to the top of the head.
Taken in front of a plain white or off-white background

照片拍摄和处理要求

Dimensions	The image dimensions must be in a square aspect ratio (the height must be equal to the width). Minimum acceptable dimensions are 600 x 600 pixels. Maximum acceptable dimensions are 1200 x 1200 pixels.
Color	The image must be in color (24 bits per pixel) in sRGB color space which is the common output for most digital cameras.
File Format	The image must be in JPEG file format
File Size	The image must be less than or equal to 240 kB (kilobytes).
Compression	The image may need to be compressed in order for it to be under the maximum file size. The compression ratio should be less than or equal to 20:1.

详细流程

浏览领事电子申请中心以申请非移民签证。
...

Saturday, November 21, 2015

FOREX Trader(FOREXTrader) insturctions

list of vocabularies

Trading Handbook

bollinger_bands

Fees

FOREX.com charges no trading commissions or transaction fees. FOREX.com charges a data fee of $15 per month if there is no trading activity or no open positions for a period of 90 days or more. Contact us if you wish to disable your account temporarily and avoid this fee.

Order Basis/Mode

Market orders:Market orders are executed at the best available price at the time the order is received. always check the market price before you make orders.

Limit Orders: Limit orders are executed at the order rate or better. Sell limit orders are filled when the bid(买家出价) reaches the requested rate; buy limit orders are filled on the offer(zxxu:to say, immidiately making the order).

Stop Orders: Stop orders become market orders when a predefined order rate is reached. Stop orders are executed at the best available price, depending on available liquidity. Buy Stop orders are filled on the offer price and Sell Stop orders are filled at the bid price.

Orders can be set to open a new position or close an existing position. To set a limit order to open a new position, you are trying to get a “better” price to buy or sell. Let’s say USDCAD is currently at 1.3000, a “better” price to buy is a price lower than 1.3000 or a “better” price to sell is a price higher than 1.3000. Stop is basically the opposite of limit, so you would set a buy order higher than the current price or a sell order lower than the current price.If you set an order to close a position, then limit means take profit and stop means stop loss.

Order Expiry

End of Day (EOD) orders automatically expire at 5pm ET on the same day the order was entered(Note:opening prices may differ significantly from the previous day's close.). Good till Cancelled (GTC) orders automatically expire on the Saturday following the 90th calendar day from the date the order was entered.

Orders Left Over the Weekend or Holidays

FOREX.com's trading hours are from Sunday at 5pm ET through Friday at 5pm ET. Orders left pending over a weekend or holiday period will not be executed until FOREX.com resumes regular trading hours.

Order Types

One Cancels Other (OCO's):A contingent(有条件的) order providing that one part of the order is cancelled if the other part is executed. If one part of the order is filled, the other is automatically cancelled.

An If/Then order provides that if the first order ("If" order) is executed, the second order ("Then" order) becomes an active unassociated single order. Unassociated orders are not attached to a trade and act independently of any position updates. In cases where the “If” order does not execute, the “Then” single order will remain dormant and will not be executed when the market reaches the specified rate. When either part of an If / Then order is cancelled, all parts of the order are cancelled as well.

An If/Then OCO provides that if the first order ("If" order) is executed, the second order ("Then" order) becomes an active unassociated OCO order. The execution of either one of the two "Then" orders automatically cancels the other. When any part of an If / Then OCO order is cancelled, including either leg of the OCO order, all parts of the order are cancelled as well.

A trailing stop allows a trade to continue to gain in value when the market price moves in a favorable direction, but automatically closes the trade if the market price suddenly moves in an unfavorable direction by a specified distance.

When the market price moves in a favorable direction, the trigger price follows the market price by the specified stop distance. If the market price moves in an unfavorable direction, the trigger price stays stationary and the distance between this price and the market price becomes smaller. If the market price continues to move in an unfavorable direction until it reaches the trigger price, an order is triggered to close the trade.

Rollovers

rollovers

什么是rollovers

当你买入一种货币对的时候，你要么支付利息，要么获得利息(charges or credits)。以下是专家的解释:" You can think of rollovers as putting money into one bank and borrowing money from another bank. For example: Let's say you want to earn on the rollover (interest differential between two countries/banks). The Bank of England (GBP)'s interest rate is 5.5%. The Bank of Japan (JPY)'s interest rate is 0.5%. If you wanted to in this circumstance you would borrow money from the Bank of Japan (0.5%) and deposit it into the Bank of England (+5.5%), thus earning 5.0% on the money you borrowed. However, the rates are compounded daily, thus causing a much smaller interest rate differential. The same principles apply when you buy (go long), on the currency pair GBP/JPY. Essentially you are buying the GBP (the base currency) and selling JPY (the counter currency) at the same time. Because the interest rate is currently higher on the GBP (Bank of England) than the JPY (Bank of Japan), you will earn interest on the position when rolled over.... The exception is a position opened and held overnight on Wednesday. The normal value date would be Saturday（not next day）; because banks are closed on Saturday the value date is actually the following Monday. Due to the weekend, positions held overnight on Wednesday incur or earn an extra two days of interest. Trades with a value date that falls on a holiday will also incur or earn additional interest.... "

rollover总是在16:59进行，也就是加拿大14:59(冬令时)，所以在这个时间点之前平仓就可以避免rollovers问题。

如何确定rollovers

加拿大人最好在http://www.forex.com/ca/trading-platforms/forextrader/pricing/rollovers.html查看每天的rollovers(Rollovers are calculated based on 10,000 position, and amounts are in USD), 或者在forex客户端查看。

影响rollovers的条件

The interest rate differentials between the country's associated with the pair you're trading. Have a glance to http://www.global-rates.com/interest-rates/central-banks/central-banks.aspx as a quick reference.
the day of the week(一般来说在周三最有利)

以下几点要注意:

FOREX.com 会对各国银行interest rate进行修正，这也是他们的赚点之一。
对于当前利息差别很大的两个国家,每天的rollover值变化不大。
即使是高级客户也不享受rollovers的优惠。

Thursday, November 19, 2015

Exponential moving average

Exponential moving averages reduce the lag by applying more weight to recent prices. The weighting applied to the most recent price depends on the number of periods in the moving average. There are three steps to calculating an exponential moving average. First, calculate the simple moving average. An exponential moving average (EMA) has to start somewhere so a simple moving average is used as the previous period's EMA in the first calculation. Second, calculate the weighting multiplier. Third, calculate the exponential moving average. The formula below is for a 10-day EMA.


SMA: 10 period sum / 10 

Multiplier: (2 / (Time periods + 1) ) = (2 / (10 + 1) ) = 0.1818 (18.18%)

EMA: {Close - EMA(previous day)} x multiplier + EMA(previous day).

Monday, November 16, 2015

BC省购买Townhouse指南

前期准备

术语扫盲

分契物业: 分契物业（strata）和共管物业（condominium）这两个词的含义相同。卑诗省是北美唯一使用“strata”而非“condominium”的地区。
分契单位/单元(strata lot): 购买房子的时候最好记住这个号码，比如strata lot 04.
owner of strata lot: 业主
strata corporation: 物业公司，即(帮助)管理业主的物业的公司.
MSL(Multiple Listing Service): 我们经常说MSL号(MSL Number/MSL #)是由MSL Department统一编制的，很多地产网可以通过这个编号来直接搜索房源

选房指标

价格:一般来说首付都是20%,那么以12万的首付来算，能买的房子是12*5=60万，也就是应该贷48万；而以13万的首付来算，能买的房子是13*5=65万，也就是应该贷52万;
周边环境
卧室数量:一般来说，3口之家再加父母需要3间房，所以加上书房一共需要4间房。
主卧一定要有浴缸
一定要有煤气
小院休闲待客区不能过小
离高压线、变压器等过近?
离危险源(比如湖、森林)过近?
地势过低?
不考虑治安不好的地区
临近常态噪声源(比如铁轨)?
周边有墓地或者屋内死过人?
各种家用设施比如冰箱、空调是否完好。
价面比(面积要取单层面积，不要算总面积!)
成交价格对比
最好不要中间的Townhouse(Townhouse一般都是好几个相连)
小孩上学问题

重要文件需要在相中房子以后向中介索取

Form-B

要特别注意物业公司是否陷入法律和经纪纠纷。

要注意前业主是否还有未交完的钱。

要注意物业当年的超支预算。

要注意物业是否允许出租

Land title(土地所有权) search

这个文件中如下重要内容:

搜索(search)的具体时间(当然越近约好)
房子属于的城市，比如Surrey, Burnaby(注意这跟注册没有关系，温哥华的房子一般都注册在new westminster)
MSL号
房主名(如果有多个房主一般会用地址符间隔开)
房主邮寄地址(如果房主住在里面一般也是他的住址，但既然是在售房源，此地址一般来说不是房源地址)

Property disclosure statement (PDS)

这个文件中卖家会回答房子有关的一切问题，也是成交之前需要获取的重要文件。