knowledge to evaluate the runner system of its temperature
distribution and the effect on products. The integrated design
of multi-cavity plastic injection mold hot-runner has been
realized by the integration of necessary structure information
and analysis of the system.
II.  KU INFORMATIONAL EXPRESSION OF HOT-RUNNER DESIGN
Definition 1   Knowledge Unit (KU): Knowledge unit is
the subset of knowledge that describes a specified object or
event. It illustrates the content, structure features, problem
description, reasoning rules and solutions of the object or the
event. KU is the basic element of product design knowledge
system. It expresses the conceptual information, and
effectively structuralizes information units of the product. KU
can be subpided into atom knowledge unit (AKU), gene
knowledge unit (GKU), and complex knowledge unit (CKU).
With the concept of ‘attribute’, generalized definition in
mathematical format can be used for the units to describe
status, feature, or character of an object or an event, or to
describe the approaches or process of problem solving.
Definition 2 Atom Knowledge Unit (AKU): AKU is the
minimal component of Knowledge Unit, which is used to
describe the basic state of knowledge existence, i.e., the
description of the basic knowledge in design, such as property,
state, characteristic, etc. AKU can be expressed as:
Assume that A is the set of the name of properties, and a
represent the property. For each aA, there is a corresponding
domain D.  The  definition  of AKU can be expressed as the
following three methods:
1) a=v, where aA,  VD. In terminology, it means the
value of  a equals  v, where  V  belongs to the subsets of  D,
therefore, a=V can be treated as a definition for abstract data
type.
2) aV, where aA, VD. In terminology, it means  a
obtains its value in V.
3) a = x, where aA,  x is a variable. In terminology, it
means a equals the value of variable x, and x varies in D.
Definition 3 Gene KU (GKU): GKU is adopted to
describe the evaluation of object constitution, target properties
or any entity, including one or more atom knowledge units
and other knowledge of the construction. GKU is utilized in
applications of simple knowledge domain and inference rules
in the process of design. GKU is expressed as: [fname, (Ka1,
Ka2, ,Kan)], where fname is the designation, representing a
GKU, and Kai is AKU, representing the evaluation of property
of GKU in terminology.
Definition 4 Complex KU(CKU):  CKU is the
knowledge units including AKU and GKU, which can
describe the knowledge domain and inferential methods
generally.
Definition 5   Structure Unit (SU): SU is a type of KU
that communicates conceptual design and structure design,
and is the structural subset that describes a certain product. It
contains the information about attribute, status, and feature
etc. transferred by conceptual design. Corresponding to KU,
SU can be classified into atom structure unit (ASU), gene
structure unit (GSU), and complex structure unit (CSU).
Multi-cavity plastic injection mold can be an example.
Multi-cavity molds are usually designed for mass production
to improve efficiency. Each mold has 2 cavities, 3 cavities, 4
cavities, 6 cavities, … 32 cavities, 48 cavities, 64 cavities or
even more thus producing several parts with each cycle.
During the design process of this type of mold, the expression
based on SU is that: ASU consists of basic conceptual
information attributes about gate, nozzle, and runner plate
(which consists of structure, material, dimensions, shape, 塑料注射模热流道设计英文文献和中文翻译(2):http://www.youerw.com/fanyi/lunwen_6870.html