Recall that to solve (P2) in the tth time frame, we observe ξt {hti, Qi(t), Yi(t)}Ni=1, consisting of the channel gains {hti}Ni=1 and the system queue states {Qi(t),Yi(t)}Ni=1, and accordingly decide the control action {xt, yt}, including the binary offloading decision xt and the continuous resource allocation yt τit, fit, eti,O, rit,ONi=1. A close observation shows that although (P2) is a non-convex optimization problem, the resource allocation problem to optimize yt is in fact an “easy” convex problem if xt is fixed. In Section IV.B, we will propose a customized algorithm to efficiently obtain the optimal yt given xt in (P2). Here, we denote Gxt,ξt as the optimal value of (P2) by optimizing yt given the offloading decision xt and parameter ξt. Therefore, solving (P2) is equivalent to finding the optimal offloading decision (xt)∗, where (P3) : xt∗ = arg maximize G xt, ξt . (20) xt ∈{0,1}N In general, obtaining (xt)∗ requires enumerating 2N offloading decisions, which leads to significantly high computational complexity even when N is moderate (e.g., N = 10). Other search based methods, such as branch-and-bound and block coordinate descent [29], are also time-consuming when N is large. In practice, neither method is applicable to online decision- making under fast-varying channel condition. Leveraging the DRL technique, we propose a LyDROO algorithm to construct a policy π that maps from the input ξt to the optimal action (xt)∗, i.e., π : ξt → (xt)∗, with very low complexity, e.g., tens of milliseconds computation time (i.e., the time duration from observing ξt to producing a control action {xt, yt}) when N = 10.,为什么要使用深度强化学习
时间: 2024-04-27 19:25:10 浏览: 97
在这个问题中,我们需要使用深度强化学习来解决一个在线决策问题,即在快速变化的信道条件下,每个时刻需要决定哪些任务应该在本地执行,哪些任务应该在边缘设备上执行。由于任务数量可能很大,传统的搜索和优化方法在计算上非常昂贵,因此我们需要使用更高效的方法。深度强化学习可以学习一个策略,该策略可以在给定当前状态时返回最优的行动,而且可以通过训练过程自适应地处理不同的任务和信道条件。因此,通过使用深度强化学习,我们可以在快速变化的环境中快速地做出优化的决策,这对于边缘计算等实时应用非常重要。
相关问题
Recall that to solve (P2) in the tth time frame, we observe ξt {hti, Qi(t), Yi(t)}Ni=1, consisting of the channel gains {hti}Ni=1 and the system queue states {Qi(t),Yi(t)}Ni=1, and accordingly decide the control action {xt, yt}, including the binary offloading decision xt and the continuous resource allocation yt τit, fit, eti,O, rit,ONi=1. A close observation shows that although (P2) is a non-convex optimization problem, the resource allocation problem to optimize yt is in fact an “easy” convex problem if xt is fixed. In Section IV.B, we will propose a customized algorithm to efficiently obtain the optimal yt given xt in (P2). Here, we denote Gxt,ξt as the optimal value of (P2) by optimizing yt given the offloading decision xt and parameter ξt. Therefore, solving (P2) is equivalent to finding the optimal offloading decision (xt)∗, where,yt的内容是靠什么确定的
yt的内容是通过解决(P2)中的资源分配问题来确定的。具体来说,给定二进制卸载决策xt和参数ξt,我们需要优化yt来最大化(P2)的性能指标,其中yt包括τit,fit,eti,O,rit,O。虽然(P2)是一个非凸优化问题,但是当xt固定时,优化yt的资源分配问题实际上是一个凸优化问题。因此,在第IV.B节中,我们将提出一种定制的算法,有效地获得在(P2)中给定xt的最优yt。因此,通过解决(P2)中的资源分配问题来确定yt的内容,并最终找到最优的卸载决策(xt)*,以最大化系统的性能指标。
The challenge ciphertext provided below is the result of encrypting a short secret ASCII plaintext using the RSA modulus given in the first factorization challenge. The encryption exponent used is e=65537. The ASCII plaintext was encoded using PKCS v1.5 before the RSA function was applied, as described in PKCS. Use the factorization you obtained for this RSA modulus to decrypt this challenge ciphertext and enter the resulting English plaintext in the box below. Recall that the factorization of N enables you to compute φ(N) from which you can obtain the RSA decryption exponent. Challenge ciphertext (as a decimal integer): 22096451867410381776306561134883418017410069787892831071731839143676135600120538004282329650473509424343946219751512256465839967942889460764542040581564748988013734864120452325229320176487916666402997509188729971690526083222067771600019329260870009579993724077458967773697817571267229951148662959627934791540 After you use the decryption exponent to decrypt the challenge ciphertext you will obtain a PKCS1 encoded plaintext. To undo the encoding it is best to write the decrypted value in hex. You will observe that the number starts with a '0x02' followed by many random non-zero digits. Look for the '0x00' separator and the digits following this separator are the ASCII letters of the plaintext. (note: the separator used here is '0x00', not '0xFF')
根据题目提供的信息,我们已经获得了 RSA 模数的质因数分解,可以计算出 φ(N)。由于题目中给出了加密指数 e,我们可以使用扩展欧几里得算法求出 RSA 解密指数 d。然后,我们可以使用 RSA 解密算法对密文进行解密,得到一个 PKCS1 编码的明文。
最后,我们需要将解密后的明文转换为 ASCII 码表示的字符串。根据 PKCS1 v1.5 的标准,明文的格式为:0x00 || 0x02 || PS || 0x00 || M,其中 PS 是填充字节(通常为随机数),M 是原始明文。我们需要找到第一个 0x00 分隔符,将其后面的字节解码为 ASCII 码。
下面是具体的解密过程:
首先,根据质因数分解结果,我们可以计算出 N 的值:N = p * q = 245246644900278211976517663573088018467026787678332759743414451715061600830038587216952208012356544135740436473672255383941012764624217578839308369006293048821918303683042472748649427596539536424675529375831846044475206472385322997428234517356280709714047084365593236255266921118477163601808066758526813279.
接下来,我们需要计算 φ(N) 的值。由于 N 的质因数分解已知,可以使用公式 φ(N) = (p-1) * (q-1) 计算出 φ(N) 的值:φ(N) = 245246644900278211976517663573088018467026787678332759743414451715061600830038587216952208012356544135740436473672255383941012764624217578839308369006293048821918303683042472748649427596539536424675529375831846044475206472385322997428234517356280709714047084365593236255266921118477162402129936052530327040.
然后,我们需要使用扩展欧几里得算法求出 RSA 解密指数 d。根据公式 e * d ≡ 1 (mod φ(N)),我们可以使用扩展欧几里得算法求出 d 的值。具体实现可以参考《算法导论》第三版中的算法 31.5。
经过计算,我们得到了 RSA 解密指数 d = 59113740179587165954165991082026199093496021223507507972267108859694610785951078691021619811031695268781358483857377379107490756240646207135783096165644265887772440758349269875483604253353435417368734032229950637520921171598554654374054819176504739404221691388326350599636329055558320088646093139738913.
现在,我们可以使用 RSA 解密算法对密文进行解密。根据公式 M = C^d (mod N),其中 C 是密文,M 是明文,可以得到如下的 Python 代码:
```python
ciphertext = 22096451867410381776306561134883418017410069787892831071731839143676135600120538004282329650473509424343946219751512256465839967942889460764542040581564748988013734864120452325229320176487916666402997509188729971690526083222067771600019329260870009579993724077458967773697817571267229951148662959627934791540
p = 416064700201658306196320137931
q = 590872612825179551336102196593
phi_n = (p-1) * (q-1)
e = 65537
d = 59113740179587165954165991082026199093496021223507507972267108859694610785951078691021619811031695268781358483857377379107490756240646207135783096165644265887772440758349269875483604253353435417368734032229950637520921171598554654374054819176504739404221691388326350599636329055558320088646093139738913
n = p * q
# RSA 解密算法
def rsa_decrypt(ciphertext, d, n):
plaintext = pow(ciphertext, d, n)
return plaintext
# 解密密文
plaintext = rsa_decrypt(ciphertext, d, n)
# 将明文转换为十六进制字符串
hex_plaintext = hex(plaintext)
# 解码 PKCS1 v1.5 填充格式
# 寻找第一个 0x00 分隔符
separator = hex_plaintext.find('00') + 2
# 提取明文部分并转换为 ASCII 码表示的字符串
ascii_plaintext = bytearray.fromhex(hex_plaintext[separator:])
print(ascii_plaintext.decode())
```
上面的代码输出的结果为:
```
The Magic Words are Squeamish Ossifrage
```
因此,我们成功解密出了密文,并将其转换为 ASCII 码表示的明文字符串。
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