là số không. Cơ chế đào tạo các trọng lượng sẽ được mô tả sau. Giả định cuối cùng là giá trị ban đầu cho F là số không. Hãy xem xét những gì xảy ra khi Qn được áp dụng đầu tiên. Cú pháp của câu lệnh ném là: ném ngoại lệ đối tượng, đối tượng ngoại lệ phải là một đối tượng thuộc một trong các lớp con của Throwable. | 358 Spatiotemporal Pattern Classification Figure A simple two-node SCAF is shown. is zero. The mechanism for training these weights will be described later. The final assumption is that the initial value for T is zero. Consider what happens when Q11 is applied first. The net input to unit 1 is u Qll 12 2 - T t 1 o - r i where we have explicitly shown gamma as a function of time. According to Eqs. through -----axỵ b l - r so x begins to increase since r and . are initially zero. The net input to unit 2 is Ỉ2 net 2 Qll W2iaq T t 0 Xi - T t Thus 2 also begins to rise due to the positive contribution from x Since both x and a 2 are increasing from the start the total activity in the network x X2 increases quickly. Under these conditions T t will begin to increase according to Eq. . The Sequential Competitive Avalanche Field 359 After a short time we remove Q11 and present Q12- xl will begin to decay but slowly with respect to its rise time. Now we calculate Il net and again I .net zl Q 2 T t 0 0 - T t z2 Ql2 m21X r 0 1 X - r t Using Eqs. through again at cax 1 and 2 6 1 xl D so xl continues to decay but In will continue to rise until 1 xl r t . Figure a shows how xl and .7 2 evolve as a function of time. A similar analysis can be used to evaluate the network output for the opposite sequence of input vectors. When Q 2 is presented first X 2 will increase. xl remains at zero since -T t and thus .7 1 cax . The total activity in the system is not sufficient to cause T i to rise. When Qn is presented the input to unit 1 is 11 1. Even though Z2 is nonzero the connection weight is zero so Xi does not contribute to the input to unit I. xl begins to rise and r t begins to rise in response to the increasing total activity. In this case r does not increase as much as it did in the first example. Figure b shows the behavior of xl andat2 for this example. The values of T t for both cases are shown in Figure .
