diff --git a/imperative/python/megengine/functional/__init__.py b/imperative/python/megengine/functional/__init__.py
index 0a2b037d4d4f02d0d03f24daf49d19e3d0e2eab8..c7e869f931022895cfa07aaee3ec618ab2ae663e 100644
--- a/imperative/python/megengine/functional/__init__.py
+++ b/imperative/python/megengine/functional/__init__.py
@@ -9,17 +9,7 @@
 # pylint: disable=redefined-builtin
 from .elemwise import *
 from .graph import add_update
-from .loss import (
-    binary_cross_entropy,
-    cross_entropy,
-    cross_entropy_with_softmax,
-    hinge_loss,
-    l1_loss,
-    nll_loss,
-    smooth_l1_loss,
-    square_loss,
-    triplet_margin_loss,
-)
+from .loss import *
 from .math import *
 from .nn import *
 from .quantized import conv_bias_activation
diff --git a/imperative/python/megengine/functional/elemwise.py b/imperative/python/megengine/functional/elemwise.py
index bc7c68f8630bbfb9b85fdc4ccf594d96b19399dc..f77a828a6eee81b55da011941d913ae46b86c17c 100644
--- a/imperative/python/megengine/functional/elemwise.py
+++ b/imperative/python/megengine/functional/elemwise.py
@@ -25,10 +25,6 @@ __all__ = [
     "asinh",
     "acosh",
     "atanh",
-    "bitwise_and",  # TODO
-    "bitwise_not",  # TODO
-    "bitwise_or",  # TODO
-    "bitwise_xor",  # TODO
     "ceil",
     "clamp",
     "cos",
@@ -339,22 +335,6 @@ def right_shift(x, y):
     return _elwise(x, y, mode="shl")
 
 
-def bitwise_and(x, y):
-    raise NotImplementedError
-
-
-def bitwise_not(x):
-    raise NotImplementedError
-
-
-def bitwise_or(x, y):
-    raise NotImplementedError
-
-
-def bitwise_xor(x, y):
-    raise NotImplementedError
-
-
 # logical functions
 
 
diff --git a/imperative/python/megengine/functional/loss.py b/imperative/python/megengine/functional/loss.py
index b98fcfc7fa8defe810885187573e6470dfe353ad..d7d4aed874413469420eff40c8208c95228747ef 100644
--- a/imperative/python/megengine/functional/loss.py
+++ b/imperative/python/megengine/functional/loss.py
@@ -15,6 +15,14 @@ from .nn import assert_equal, indexing_one_hot
 from .tensor import where
 from .utils import zero_grad
 
+__all__ = [
+    "l1_loss",
+    "square_loss",
+    "cross_entropy_with_softmax",
+    "binary_cross_entropy",
+    "hinge_loss",
+]
+
 
 def l1_loss(pred: Tensor, label: Tensor) -> Tensor:
     r"""
@@ -93,59 +101,6 @@ def square_loss(pred: Tensor, label: Tensor) -> Tensor:
     return (diff ** 2).mean()
 
 
-def cross_entropy(
-    inp: Tensor, target: Tensor, axis: int = 1, ignore_index: int = -1
-) -> Tensor:
-    r"""
-    Returns the cross entropy loss in a classification problem.
-
-    .. math:: \textrm{CrossEntropy}(x, y) = - \sum_{i} y_i\log(x_i)
-
-    :param inp: The input tensor representing the predicted probability.
-    :param label: The input tensor representing the classification label.
-    :param axis: An axis along which cross_entropy will be applied. Default: 1
-    :param ignore_index: Specifies a target value that is ignored and does not contribute to the input gradient. Default: -1
-
-    Examples:
-
-    .. testcode::
-
-        import numpy as np
-        from megengine import tensor
-        import megengine.functional as F
-
-        data_shape = (1, 2)
-        label_shape = (1, )
-
-        pred = tensor(np.array([0.5, 0.5], dtype=np.float32).reshape(data_shape))
-        label = tensor(np.ones(label_shape, dtype=np.int32))
-        loss = F.cross_entropy(pred, label)
-        print(loss.numpy())
-
-    Outputs:
-
-    .. testoutput::
-
-        [0.69]
-
-    """
-    raise NotImplementedError
-    # n0 = inp.ndim
-    # n1 = target.ndim
-    # assert n0 == n1 + 1, (
-    #     "target ndim must be one less than input ndim; input_ndim={} "
-    #     "target_ndim={}".format(n0, n1)
-    # )
-
-    # if ignore_index != -1:
-    #     mask = 1 - equal(target, ignore_index)
-    #     target = target * mask
-    #     loss = -log(indexing_one_hot(inp, target, axis)) * mask
-    #     return loss.sum() / maximum(mask.sum(), 1.0)
-    # else:
-    #     return -log(indexing_one_hot(inp, target, axis)).mean()
-
-
 def cross_entropy_with_softmax(
     pred: Tensor, label: Tensor, axis: int = 1, label_smooth: float = 0
 ) -> Tensor:
@@ -189,49 +144,6 @@ def cross_entropy_with_softmax(
     return (log(down) - up).mean()
 
 
-def triplet_margin_loss(
-    anchor: Tensor, positive: Tensor, negative: Tensor, margin: float = 1.0, p: int = 2
-) -> Tensor:
-    r"""
-    Creates a criterion that measures the triplet loss given an input tensors.
-
-    .. math::
-
-        L(a, p, n) = max\left\{d\left(a_{i},p_{i}\right)-d\left(a_{i}, n_{i}\right)+margin, 0\right\},\
-        d\left(x_{i},y_{i}\right)=\left\|x_{i}-y_{i}\right\|_{p}
-
-    :param anchor: The input tensor representing the anchor samples.
-    :param positive: The input tensor representing the positive samples.
-    :param negative: The input tensor representing the negative samples.
-    :param margin: Default: 1.0
-    :param p: The norm degree for pairwise distance. Default: 2.0
-    """
-    s0 = anchor.shapeof()
-    s1 = positive.shapeof()
-    s2 = negative.shapeof()
-    assert_equal(s0, s1)
-    assert_equal(s1, s2)
-
-    n0 = anchor.ndim
-    n1 = positive.ndim
-    n2 = negative.ndim
-    assert n0 == 2 and n1 == 2 and n2 == 2, (
-        "anchor ndim, positive ndim, and negative ndim must be 2; "
-        "anchor_ndim={} positive_ndim={} negative_ndim={}".format(n0, n1, n2)
-    )
-    assert p > 0, "a margin with a value greater than 0; p={}".format(p)
-
-    diff0 = abs(anchor - positive)
-    diff1 = abs(anchor - negative)
-
-    d1 = power(power(diff0, p).sum(axis=1, keepdims=True), 1 / p)
-    d2 = power(power(diff1, p).sum(axis=1, keepdims=True), 1 / p)
-
-    loss = maximum(d1 - d2 + margin, 0)
-
-    return loss.mean()
-
-
 def binary_cross_entropy(pred: Tensor, label: Tensor) -> Tensor:
     r"""Function that measures the Binary Cross Entropy between the target and the prediction.
 
@@ -244,59 +156,6 @@ def binary_cross_entropy(pred: Tensor, label: Tensor) -> Tensor:
     return -1.0 * (label * log(pred) + (1.0 - label) * log(1 - pred)).mean()
 
 
-def nll_loss(
-    pred: Tensor, label: Tensor, axis: int = 1, ignore_index: int = -1
-) -> Tensor:
-    r"""
-    The negative log likelihood loss.
-
-    :param pred: The predicted result from model.
-    :param label: The ground truth to compare.
-
-    Examples:
-
-    .. testcode::
-
-        import numpy as np
-        from megengine import tensor
-        import megengine.functional as F
-        data_shape = (2, 2)
-        label_shape = (2, )
-
-        data = tensor(
-            np.array([[1, 0.5], [0.3, 1.2]], dtype=np.float32).reshape(data_shape),
-        )
-        label = tensor(
-            np.ones(label_shape, dtype=np.int32)
-        )
-        pred = F.log(F.softmax(data))
-        loss1 = F.nll_loss(pred, label)
-        loss2 = F.cross_entropy_with_softmax(data, label)
-        print(loss1.numpy(), loss2.numpy())
-
-    Outputs:
-
-    .. testoutput::
-
-        [0.6576154] [0.6576154]
-
-    """
-    raise NotImplementedError
-    # n0 = pred.ndim
-    # n1 = label.ndim
-    # assert n0 == n1 + 1, (
-    #     "target ndim must be one less than input ndim; input_ndim={} "
-    #     "target_ndim={}".format(n0, n1)
-    # )
-
-    # mask = 1.0 - equal(label, ignore_index)
-    # label = label * mask
-
-    # loss = indexing_one_hot(pred, label, axis) * mask
-
-    # return -1.0 * loss.sum() / maximum(mask.sum(), 1.0)
-
-
 def hinge_loss(pred: Tensor, label: Tensor, norm: str = "L1") -> Tensor:
     r"""
     Caculate the hinge loss which is often used in SVMs.
@@ -337,53 +196,3 @@ def hinge_loss(pred: Tensor, label: Tensor, norm: str = "L1") -> Tensor:
         return loss.sum(axis=1).mean()
     else:
         return (loss ** 2).sum(axis=1).mean()
-
-
-def smooth_l1_loss(pred: Tensor, label: Tensor) -> Tensor:
-    r"""
-    Caculate the smooth l1 loss proposed in `Fast R-CNN paper by Ross Girshick`.
-
-    The smooth l1 loss can be described as:
-
-    .. math::
-        \text{loss}(x, y) = \frac{1}{n} \sum_{i} l_{i}
-
-    where :math:`l_{i}` is given by:
-
-    .. math::
-        l_{i} =
-        \begin{cases}
-        0.5 (x_i - y_i)^2, & \text{if } |x_i - y_i| < 1 \\
-        |x_i - y_i| - 0.5, & \text{otherwise }
-        \end{cases}
-
-    :param pred: The predicted result from model.
-    :param label: The ground truth to compare.
-
-    Examples:
-
-    .. testcode::
-
-        from megengine import tensor
-        import megengine.functional as F
-
-        pred = tensor([[0.5, -0.5, 0.1], [-0.6, 0.7, 0.8]])
-        label = tensor([[0.4, 1.5, 1.2], [0., 0.1, 2.2]])
-
-        loss = F.smooth_l1_loss(pred, label)
-
-        print(loss.numpy())
-
-    Outputs:
-
-    .. testoutput::
-
-        [0.5608334]
-    """
-    raise NotImplementedError
-    # diff = abs(pred - label)
-    # l2_loss = 0.5 * (diff ** 2)
-    # l1_loss = diff - 0.5
-    # mask = diff < 1
-    # loss = where(mask, l2_loss, l1_loss)
-    # return loss.mean()
diff --git a/imperative/python/megengine/functional/math.py b/imperative/python/megengine/functional/math.py
index bc7d9dd88dc80967e1d60df7ea1924b2a248b67f..dbf971d48de04b5130faee2c85f61f19cbb60742 100644
--- a/imperative/python/megengine/functional/math.py
+++ b/imperative/python/megengine/functional/math.py
@@ -21,47 +21,26 @@ from .elemwise import clamp, exp, log, log1p
 from .tensor import remove_axis, reshape
 
 __all__ = [
-    "all",  # TODO
-    "all_close",  # TODO
-    "any",  # TODO
     "argmax",
     "argmin",
     "argsort",
     "isinf",
-    "isnan",  # TODO
+    "isnan",
     "max",
     "mean",
-    "median",  # TODO
     "min",
     "norm",
     "normalize",
     "prod",
-    "sign",  # TODO
+    "sign",
     "sort",
     "std",
     "sum",
     "topk",
-    "unique",  # TODO
     "var",
 ]
 
 
-def all(inp):
-    raise NotImplementedError
-
-
-def all_close(inp):
-    raise NotImplementedError
-
-
-def any(inp):
-    raise NotImplementedError
-
-
-def unique(inp):
-    raise NotImplementedError
-
-
 def isnan(inp: Tensor) -> Tensor:
     r"""Returns a new tensor representing if each element is NaN or not.
 
@@ -77,15 +56,14 @@ def isnan(inp: Tensor) -> Tensor:
 
         x = tensor([1, float("nan"), 0])
 
-        print(F.isnan(x))
+        print(F.isnan(x).numpy())
 
     .. testoutput::
 
-        Tensor([0 1 0], dtype=uint8)
+        [False  True False]
 
     """
-    raise NotImplementedError
-    # return (inp != inp).astype("uint8")
+    return inp != inp
 
 
 def isinf(inp: Tensor) -> Tensor:
@@ -103,18 +81,39 @@ def isinf(inp: Tensor) -> Tensor:
 
         x = tensor([1, float("inf"), 0])
 
-        print(F.isinf(x))
+        print(F.isinf(x).numpy())
 
     .. testoutput::
 
-        Tensor([0 1 0], dtype=uint8)
+        [False  True False]
 
     """
-    return (abs(inp).astype("float32") == float("inf")).astype("uint8")
+    return abs(inp).astype("float32") == float("inf")
 
 
 def sign(inp: Tensor):
-    raise NotImplementedError
+    r"""Returns sign of each element in the input tensor.
+
+    :param: inp
+    :return: a sign tensor.
+
+    Examples:
+
+    .. testcode::
+
+        from megengine import tensor
+        import megengine.functional as F
+
+        x = tensor([1, -1, 0])
+
+        print(F.sign(x).numpy())
+
+    .. testoutput::
+
+        [ 1 -1  0]
+
+    """
+    return (inp > 0).astype(inp.dtype) - (inp < 0).astype(inp.dtype)
 
 
 def sum(
diff --git a/imperative/python/megengine/functional/nn.py b/imperative/python/megengine/functional/nn.py
index 27e1b91722dd882f72d3aba01ae4f78fa7189a37..4eb60883e9faa403e5fec6350be5082483ace6b0 100644
--- a/imperative/python/megengine/functional/nn.py
+++ b/imperative/python/megengine/functional/nn.py
@@ -623,7 +623,7 @@ def batch_norm2d(
         Default: True
 
     """
-    from .tensor import expand_dims, squeeze, broadcast
+    from .tensor import add_axis, remove_axis, broadcast
 
     def full(value):
         C = data.shape[1]
@@ -633,7 +633,7 @@ def batch_norm2d(
     def expand_or_full(x, value):
         if x is None:
             return full(value)
-        return expand_dims(x, [0, 2, 3])
+        return add_axis(x, [0, 2, 3])
 
     def make_full_if_none(x, value):
         if x is None:
@@ -1229,14 +1229,14 @@ def interpolate(
     return ret
 
 
-def dropout(inp: Tensor, drop_prob: float, rescale: bool = True) -> Tensor:
+def dropout(inp: Tensor, drop_prob: float, training: bool = True) -> Tensor:
     """
     Returns a new tensor where each of the elements are randomly set to zero
     with probability P = ``drop_prob``. Optionally rescale the output tensor.
 
     :param inp: The input tensor
     :param drop_prob: The probability to drop (set to zero) a single element
-    :param rescale: The default behavior of ``dropout`` during training is to rescale the output,
+    :param training: The default behavior of ``dropout`` during training is to rescale the output,
         then it can be replaced by an :class:`~.Identity` during inference, default to True.
     :return: The output tensor
 
@@ -1266,7 +1266,7 @@ def dropout(inp: Tensor, drop_prob: float, rescale: bool = True) -> Tensor:
     rv = uniform(inp.shape)
     mask = rv > drop_prob
     inp *= mask.astype(inp.dtype)
-    if rescale:
+    if training:
         inp *= 1 / (1 - drop_prob)
     return inp
 
diff --git a/imperative/python/megengine/functional/tensor.py b/imperative/python/megengine/functional/tensor.py
index e63ed3462d18c98267b4f8d4817d563f66c889d9..588a5723f000cb33c32c13d41cbbdabd9dfe94a3 100644
--- a/imperative/python/megengine/functional/tensor.py
+++ b/imperative/python/megengine/functional/tensor.py
@@ -14,6 +14,7 @@ from typing import Iterable, List, Optional, Sequence, Tuple, Union
 import numpy as np
 
 from ..core._imperative_rt import CompNode
+from ..core._wrap import device as as_device
 from ..core.ops import builtin
 from ..core.ops._internal import param_defs as P
 from ..core.ops.special import Const
@@ -30,31 +31,32 @@ from ..tensor import Tensor
 from .elemwise import ceil
 
 __all__ = [
-    "add_axis",  # expand_dims
+    "add_axis",
     "arange",
     "broadcast",
     "concat",
     "cond_take",
-    "dimshuffle",  # transpose, permute
+    "dimshuffle",
     "expand_dims",
+    "eye",
     "full",
     "full_like",
     "gather",
-    "eye",
     "linspace",
     "ones",
     "ones_like",
-    "remove_axis",  # squeeze
+    "param_pack_concat",
+    "param_pack_split",
+    "reshape",
+    "remove_axis",
     "split",
     "squeeze",
     "stack",
-    "reshape",
     "scatter",
+    "transpose",
     "where",
     "zeros",
     "zeros_like",
-    "param_pack_split",
-    "param_pack_concat",
 ]
 
 
@@ -97,6 +99,8 @@ def eye(n: int, *, dtype=None, device: Optional[CompNode] = None) -> Tensor:
 
 
 def full(shape, value, dtype="float32", device=None):
+    if isinstance(shape, int):
+        shape = (shape,)
     if device is None:
         device = get_default_device()
     (x,) = Const(value, dtype=dtype, device=device)(
@@ -196,16 +200,13 @@ def broadcast(inp: Tensor, shape: Union[int, Iterable[int]]) -> Tensor:
     return result
 
 
-def concat(
-    inps: Iterable[Tensor], axis: int = 0, device: Optional[CompNode] = None,
-) -> Tensor:
+def concat(inps: Iterable[Tensor], axis: int = 0, device=None) -> Tensor:
     r"""
     Concat some tensors
 
     :param inps: Input tensors to concat
     :param axis: the dimension over which the tensors are concatenated. Default: 0
     :param device: The comp node output on. Default: None
-    :param comp_graph: The graph in which output is. Default: None
     :return: The output tensor
 
     Examples:
@@ -235,7 +236,9 @@ def concat(
         return inps[0]
 
     dtype = dtype_promotion(inps)
-    device = get_device(inps)
+    if device is None:
+        device = get_device(inps)
+    device = as_device(device)
 
     def convert(x):
         return convert_single_value(x, inps, dtype=dtype)
@@ -245,12 +248,13 @@ def concat(
     return result
 
 
-def stack(inps, axis=0):
+def stack(inps, axis=0, device=None):
     """Concats a sequence of tensors along a new axis.
     The input tensors must have the same shape.
 
     :param inps: The input tensors.
     :param axis: Which axis will be concatenated.
+    :param device: The comp node output on. Default: None
     :return: The output concatenated tensor.
 
     Examples:
@@ -283,7 +287,7 @@ def stack(inps, axis=0):
             raise ValueError("All input tensors must have the same shape")
 
     inps = [add_axis(inp, axis=axis) for inp in inps]
-    return concat(inps, axis=axis)
+    return concat(inps, axis=axis, device=device)
 
 
 def split(inp, nsplits_or_sections, axis=0):
@@ -609,7 +613,10 @@ def where(mask: Tensor, x: Tensor, y: Tensor) -> Tensor:
 
 def cond_take(mask: Tensor, x: Tensor) -> Tensor:
     r"""
-    Take elements from data if specific condition is satisfied on mask. This operator has two outputs: the first is the elements taken, and the second is the indices corresponding to those elements; they are both 1-dimensional. High-dimension input would first be flattened.
+    Take elements from data if specific condition is satisfied on mask.
+    This operator has two outputs: the first is the elements taken,
+    and the second is the indices corresponding to those elements;
+    they are both 1-dimensional. High-dimension input would first be flattened.
 
     :param mask: condition param; must be the same shape with data
     :param x: input tensor from which to take elements
@@ -692,6 +699,9 @@ def dimshuffle(inp: Tensor, pattern: Iterable[int]) -> Tensor:
     return result
 
 
+transpose = dimshuffle
+
+
 def reshape(inp: Tensor, target_shape: Iterable[int]) -> Tensor:
     r"""
     Reshape a tensor to given target shape; total number of logical elements must
@@ -748,9 +758,6 @@ def reshape(inp: Tensor, target_shape: Iterable[int]) -> Tensor:
     return x
 
 
-transpose = dimshuffle
-
-
 AxisAddRemove = builtin.AxisAddRemove
 AxisDesc = AxisAddRemove.AxisDesc
 
@@ -803,12 +810,14 @@ def add_axis(inp: Tensor, axis: Union[int, Sequence[int]]) -> Tensor:
 expand_dims = add_axis
 
 
-def remove_axis(inp: Tensor, axis: Union[int, Sequence[int]]) -> Tensor:
+def remove_axis(
+    inp: Tensor, axis: Optional[Union[int, Sequence[int]]] = None
+) -> Tensor:
     r"""
     Remove dimension of shape 1.
 
     :param inp: Input tensor
-    :param axis: Place of axis to be removed
+    :param axis: Place of axis to be removed, if None, all axis=1 will be removed. Default: None
     :return: The output tensor
 
     Examples:
@@ -897,8 +906,8 @@ def linspace(
 
 
 def arange(
-    start: Union[int, float, Tensor],
-    end: Union[int, float, Tensor],
+    start: Union[int, float, Tensor] = 0,
+    end: Optional[Union[int, float, Tensor]] = None,
     step: Union[int, float, Tensor] = 1,
     dtype="float32",
     device: Optional[CompNode] = None,
@@ -919,7 +928,7 @@ def arange(
         import numpy as np
         import megengine.functional as F
 
-        a = F.arange(1, 5, 1)
+        a = F.arange(5)
         print(a.numpy())
 
     .. testoutput::
@@ -927,6 +936,9 @@ def arange(
         [1. 2. 3. 4.]
 
     """
+    if end is None:
+        start, end = 0, start
+
     if isinstance(start, Tensor):
         start = start.astype("float32")
     if isinstance(end, Tensor):
diff --git a/imperative/python/megengine/jit/__init__.py b/imperative/python/megengine/jit/__init__.py
index c2f2bf77120ac998045233439cb04355d5f3ad83..5965fa1b817a58e0c92bfae2b9d988475528a1aa 100644
--- a/imperative/python/megengine/jit/__init__.py
+++ b/imperative/python/megengine/jit/__init__.py
@@ -1,2 +1,10 @@
+# -*- coding: utf-8 -*-
+# MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
+#
+# Copyright (c) 2014-2020 Megvii Inc. All rights reserved.
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 from .sublinear_memory_config import SublinearMemoryConfig
 from .tracing import exclude_from_trace, trace
diff --git a/imperative/python/megengine/jit/sublinear_memory_config.py b/imperative/python/megengine/jit/sublinear_memory_config.py
index 7f6a8d278bc57f6ea9a9c8bcbca023311e545e8e..54a22b18fc1184ff1a8ac0c8d20acc7eb54f1ba8 100644
--- a/imperative/python/megengine/jit/sublinear_memory_config.py
+++ b/imperative/python/megengine/jit/sublinear_memory_config.py
@@ -6,7 +6,6 @@
 # Unless required by applicable law or agreed to in writing,
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-
 from ..device import get_device_count
 
 
diff --git a/imperative/python/megengine/jit/tracing.py b/imperative/python/megengine/jit/tracing.py
index 4fc59de37eaf80386cca2896e08d65effbba9fac..a727982de73370cea86ca9d15828b6c180d2edc6 100644
--- a/imperative/python/megengine/jit/tracing.py
+++ b/imperative/python/megengine/jit/tracing.py
@@ -1,3 +1,11 @@
+# -*- coding: utf-8 -*-
+# MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
+#
+# Copyright (c) 2014-2020 Megvii Inc. All rights reserved.
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 import collections
 import contextlib
 import functools
diff --git a/imperative/python/megengine/module/init.py b/imperative/python/megengine/module/init.py
index 4c8151a4f167d1c1559e15268ab297eb4781ea2e..9fc08faa14923b9db293a9e3a475cb4b3072b51b 100644
--- a/imperative/python/megengine/module/init.py
+++ b/imperative/python/megengine/module/init.py
@@ -13,7 +13,7 @@ from typing import Optional, Tuple, Union
 import numpy as np
 
 from ..functional import full
-from ..random import gaussian, uniform
+from ..random import normal, uniform
 from ..tensor import Tensor
 
 
@@ -50,7 +50,7 @@ def uniform_(tensor: Tensor, a: float = 0.0, b: float = 1.0) -> None:
     :param a: Lower bound of the sampling interval
     :param b: Upper bound of the sampling interval
     """
-    tensor._reset(uniform(tensor.shape, low=a, high=b).astype(tensor.dtype))
+    tensor._reset(uniform(size=tensor.shape, low=a, high=b).astype(tensor.dtype))
 
 
 def normal_(tensor: Tensor, mean: float = 0.0, std: float = 1.0) -> None:
@@ -61,7 +61,7 @@ def normal_(tensor: Tensor, mean: float = 0.0, std: float = 1.0) -> None:
     :param mean: The mean of the normal distribution
     :param std: The standard deviation of the normal distribution
     """
-    tensor._reset(gaussian(tensor.shape, mean=mean, std=std).astype(tensor.dtype))
+    tensor._reset(normal(size=tensor.shape, mean=mean, std=std).astype(tensor.dtype))
 
 
 def calculate_gain(
diff --git a/imperative/python/megengine/random/__init__.py b/imperative/python/megengine/random/__init__.py
index 86c8d7979c229c7c9697098a5a70135743f15748..709329fe1391f80f393c8744f5bb11690d9559e4 100644
--- a/imperative/python/megengine/random/__init__.py
+++ b/imperative/python/megengine/random/__init__.py
@@ -6,8 +6,8 @@
 # Unless required by applicable law or agreed to in writing,
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-from .distribution import gaussian, uniform
-from .rng import manual_seed
+from .distribution import normal, uniform
+from .rng import seed
 
 # pylint: disable=undefined-variable
 del distribution, rng  # type: ignore[name-defined]
diff --git a/imperative/python/megengine/random/distribution.py b/imperative/python/megengine/random/distribution.py
index 2f4655af75a18cf7551ea4a07e14f6ed73829d47..a202c10f5e542d1b9d308c3980284c79be5c8602 100644
--- a/imperative/python/megengine/random/distribution.py
+++ b/imperative/python/megengine/random/distribution.py
@@ -15,13 +15,15 @@ from ..core.tensor import utils
 from ..core.tensor.core import apply
 from .rng import _random_seed_generator
 
-__all__ = ["gaussian", "uniform"]
+__all__ = ["normal", "uniform"]
 
 
-def gaussian(shape: Iterable[int], mean: float = 0, std: float = 1,) -> Tensor:
+def normal(
+    mean: float = 0, std: float = 1, size: Optional[Iterable[int]] = None
+) -> Tensor:
     r"""Random variable with Gaussian distribution $N(\mu, \sigma)$
 
-    :param shape: Output tensor shape
+    :param size: Output tensor size
     :param mean: The mean or expectation of the distribution
     :param std: The standard deviation of the distribution (variance = $\sigma ^ 2$)
     :return: The output tensor
@@ -33,7 +35,7 @@ def gaussian(shape: Iterable[int], mean: float = 0, std: float = 1,) -> Tensor:
         import megengine as mge
         import megengine.random as rand
 
-        x = rand.gaussian((2, 2), mean=0, std=1)
+        x = rand.normal(mean=0, std=1, size=(2, 2))
         print(x.numpy())
 
     .. testoutput::
@@ -43,17 +45,21 @@ def gaussian(shape: Iterable[int], mean: float = 0, std: float = 1,) -> Tensor:
          [-1.4939808  -1.5824696 ]]
 
     """
+    if size is None:
+        size = (1,)
     seed = _random_seed_generator().__next__()
     op = GaussianRNG(seed=seed, mean=mean, std=std)
-    shape = Tensor(shape, dtype="int32")
-    (output,) = apply(op, shape)
+    size = Tensor(size, dtype="int32")
+    (output,) = apply(op, size)
     return output
 
 
-def uniform(shape: Iterable[int], low: float = 0, high: float = 1,) -> Tensor:
+def uniform(
+    low: float = 0, high: float = 1, size: Optional[Iterable[int]] = None
+) -> Tensor:
     r"""Random variable with uniform distribution $U(0, 1)$
 
-    :param shape: Output tensor shape
+    :param size: Output tensor size
     :param low: Lower range
     :param high: Upper range
     :return: The output tensor
@@ -65,7 +71,7 @@ def uniform(shape: Iterable[int], low: float = 0, high: float = 1,) -> Tensor:
         import megengine as mge
         import megengine.random as rand
 
-        x = rand.uniform((2, 2))
+        x = rand.uniform(size=(2, 2))
         print(x.numpy())
 
     .. testoutput::
@@ -77,9 +83,11 @@ def uniform(shape: Iterable[int], low: float = 0, high: float = 1,) -> Tensor:
     """
     assert low < high, "Uniform is not defined when low >= high"
 
+    if size is None:
+        size = (1,)
     seed = _random_seed_generator().__next__()
     op = UniformRNG(seed=seed)
-    shape = Tensor(shape, dtype="int32")
-    (output,) = apply(op, shape)
+    size = Tensor(size, dtype="int32")
+    (output,) = apply(op, size)
 
     return low + (high - low) * output
diff --git a/imperative/python/megengine/random/rng.py b/imperative/python/megengine/random/rng.py
index 992c6a49565b1349ae5b171156b680cf1e644a4b..8852955ba7a36592a0b008c132b3b9c12aa3cc1e 100644
--- a/imperative/python/megengine/random/rng.py
+++ b/imperative/python/megengine/random/rng.py
@@ -17,11 +17,11 @@ def _random_seed_generator():
     if _rng is None:
         from ..distributed.group import get_rank
 
-        manual_seed(seed=int(time.time()) + get_rank())
+        seed(seed=int(time.time()) + get_rank())
     while True:
         yield _rng.random_raw()
 
 
-def manual_seed(seed: int):
+def seed(seed: int):
     global _rng  # pylint: disable=global-statement
     _rng = MT19937(seed=seed)
diff --git a/imperative/python/test/unit/functional/test_elemwise.py b/imperative/python/test/unit/functional/test_elemwise.py
index 683103fd84bbcb3e99dc029623a501144a4410cf..db7db5cc09d355959f78329713f8c15d874cd850 100644
--- a/imperative/python/test/unit/functional/test_elemwise.py
+++ b/imperative/python/test/unit/functional/test_elemwise.py
@@ -55,14 +55,20 @@ def test_clamp():
     assertTensorClose(F.clamp(tensor(x) - 3, -6, 0).numpy(), np.clip(x - 3, -6, 0))
 
 
-# def test_isnan():
-#     for case in [[1, float("nan"), 0]]:
-#         assertTensorClose(F.isnan(tensor(case)), np.isnan(case).astype("uint8"))
+def test_isnan():
+    for case in [[1, float("nan"), 0]]:
+        assertTensorClose(F.isnan(tensor(case)).numpy(), np.isnan(case))
 
 
 def test_isinf():
     for case in [[1, float("inf"), 0]]:
-        assertTensorClose(F.isinf(tensor(case)).numpy(), np.isinf(case).astype("uint8"))
+        assertTensorClose(F.isinf(tensor(case)).numpy(), np.isinf(case))
+
+
+def test_sign():
+    for case in [[1, -1, 0]]:
+        x = tensor(case)
+        assertTensorClose(F.sign(x).numpy(), np.sign(case).astype(x.dtype))
 
 
 def test_cosh():
diff --git a/imperative/python/test/unit/functional/test_tensor.py b/imperative/python/test/unit/functional/test_tensor.py
index 253e840fd0d0f02ce4097fdf12e49a6c2e616529..c53188137a4cf5eac0eda4755f4f9a98b1ddd800 100644
--- a/imperative/python/test/unit/functional/test_tensor.py
+++ b/imperative/python/test/unit/functional/test_tensor.py
@@ -110,6 +110,14 @@ def test_concat():
     opr_test(cases, run, ref_fn=lambda x, y: np.concatenate([x, y]))
 
 
+def test_concat_device():
+    data1 = tensor(np.random.random((3, 2, 2)).astype("float32"), device="cpu0")
+    data2 = tensor(np.random.random((2, 2, 2)).astype("float32"), device="cpu1")
+
+    out = F.concat([data1, data2], device="cpu0")
+    assert str(out.device).split(":")[0] == "cpu0"
+
+
 def test_stack():
     data1 = np.random.random((3, 2, 2)).astype("float32")
     data2 = np.random.random((3, 2, 2)).astype("float32")