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A Context-aware Services Mash-up System
2008 Seventh International Conference on Grid and Cooperative Computing
Yan Li
Jun Fang
Jinhua Xiong
報告者：謝侃呈
Abstract
Some domain users, especially those without IT
background, might consider participating in mash-up
process as time-consuming, even a trouble.
Context-aware services can be aware of the current
context to provide better support for the users to
mash-up or enjoy the result of mash-up.
NSIS
NSIS(National Scientific Information System)：
NSIS是中國權威的資訊系統，透過各省的資
訊節點提供科學資訊。
每個省都有各自的網站，而且具類似的功能。
Query Service必須在Service Repository註冊才
能使用，Service Repository是存放service的
metadata。
Context-aware
情境感知服務：能瞭解使用者目前的環境及狀態，根
據所蒐集的情境判斷使用者可能的需
求，然後提供使用者合適的資訊或服
務。
情境感知計算區的型態： 1. 主動情境感知計算
2. 被動情境感知計算
情境感知服務混搭系統可以看成二個部分：
1. 情境感知
2. 服務混搭
ENABLING
CONTEXT-AWARENESS
The Context Model：
PLATE
It was proposed to model context
and support context reasoning.
Context-aware
middleware
Its main role is to provide the context about current
user through Context Access API.
The Context Model：PLATE
How
Who
Where
What
When
Two-layer hierarchical Ontology Architecture
Context-aware middleware
Context retrieval module：
This module provides interfaces to source context
from providers.
Upper Ontology：
The architecture is based on PLATE model.
Reasoning：
It can be used to deduce high-level, implicit context
from low-level, explicit context.
Context Knowledge Base:
It stores context data and sub-domain ontology.
Using OWL format, the context KB can be
stored in DBMS.
Context Access API:
It provides APIs to acquire context.
情境感知服務混搭系統可以看成二個部分：
1. 情境感知
2. 服務混搭
SERVICES MASH-UP SYSTEM
Service Mash-up Portal：
Its function is to provide portal for users to
build mash-up that consists of four parts.
The second layer：
Service Mash-up Engine is responsible for
parsing user context and service selection to
invoke web services through Service Mediator.
The Service Mediator ：
It is designed to provide a transparent way for
information services Invocation.
The Service Repository ：
It is designed to store metadata of services.
It provides query APIs that can be used to gain
suitable services with context.
CASE STUDY
NSIS：It is an authoritative information system in
China that provides national scientific
information through many local information
nodes residing in respective provinces.
The farmer in Hubei Province wants to
acquire information about insect disease
prevention from this portal.
Farmer
7
2
3
5
4
1
CONCLUSION
情境感知服務混搭系統可以根據使用者的情境提供
可能需要的資訊，讓沒有IT背景的使用者也可以看
到混搭的資訊，提升取得資訊的效率；進階的使用
者則可以使用系統提供的mashup工具，創造自己所
想要的混搭結果。不論使用者有無IT背景皆能提供
良好的使用者體驗(user experience)。