Kun-Yung Lu

A hybrid genetic algorithm approach on multi-objective of assembly planning problem

Abstract In practice, modeling an assembly system often requires assigning a set of operations to a set of workstations. The aim is to optimize some performance indices of an assembly line. This assignation is usually a tedious design procedure so a significant amount of manpower is required to obtain a good work plan. Poor assembly planning may significantly increase the cost of products and reduce productivity. However, these optimization problems fall into the class of NP-hard problems. Finding an optimal solution in an acceptable time is difficult, even using a powerful computer. This study presents a hybrid genetic algorithm approach to the problems of assembly planning with various objectives, including minimizing cycle time, maximizing workload smoothness, minimizing the frequency of tool change, minimizing the number of tools and machines used, and minimizing the complexity of assembly sequences. A self-tuning method was developed to correct infeasible chromosomes. Several examples were employed to illustrate the proposed approach. Experimental results indicated that the proposed method can efficiently yield many alternative assembly plans to support the design and operation of a flexible assembly system.

A case study in the design of BTO/CTO shop floor control system

Although computerized information systems are conventionally used to control production, applying a manual approach and improper logistical assignments typically reduces operating efficiency and increases customer service response time. Satisfying the requirements of remaining competitiveness in the current marketplace, such as offering build-to-order (BTO) or configuration-to-order (CTO) services is difficult. This study presents an integrated information system for use in shop floor controlling systems (SFCS) for kitting parts, producing goods, packing finished goods and distributing them, to enhance the performance of the BTO/CTO production system. Several information technologies and devices, such as barcode system, the electronic pick-to-light picking system, electronic Kanban (eKanban), and others are adopted to support the relevant logistics. A personal computer (PC) manufacturer is used to demonstrate the proposed system. The findings of the study reveal that the proposed information system can respond to the status of the production line in real time. This responsiveness can help the production controller to make a suitable decision and quickly meet the requirements of the BTO/CTO production system.

Optimizing assembly planning through a three-stage integrated approach

Abstract This study proposes a three-stage integrated approach with heuristic working rules to assist the planner to develop a better assembly plan. In the first stage, Above Graph and transforming rules were used to create a correct Explosion Graph of the assembly models. In the second stage, a three-level relational model was developed to create a complete relational model graph and an incidence matrix. In the third stage, a mathematical model, based on a penalty index was formulated, and a revised minimum spanning table method was used to generate and evaluate a feasible assembly sequence. The example of a military system is presented to demonstrate the feasibility of the proposed method. The contribution of this study is based on a design for assembly potential applications of three-dimensional (3D) component models to assist manual or automatic assembly in a virtual environment, and allows the designer to recognize the relative position, constraints and relationships of 3D components using graph-oriented methods: Above Graph, assembly precedent diagram, and relational model graph.

Metadata management system: design and implementation

Commonly, an organizational information system may have various data types and directory formats. It usually employs different metadata formats to represent the documents. Although the metadata system can cover the different formats of documents, there still exist the integration problems in various metadata systems. This may lower the performance of data processing and impede information sharing. Research focuses on the model of using multi‐XML schema to construct an XML system framework. Through a complete hierarchical tree structure definition of inner elements, the proposed model can settle the weakness of traditional object‐oriented languages in information sharing; it can also eliminate the constraints of storage and management among heterogeneous metadata while processing different metadata information.

Intelligent warehousing management systems using multi-agent

This paper presents an agent-driven with automatic data capturing approach to support warehousing management that involves issuing shipping schedules, allocating the storage spaces, and arranging the order-picking routes. Some heuristic working rules based on class-based allocation principles in accordance with the bill of materials (BOM) are applied to guide multi-agent processing the warehousing transactions. A two-dimensional (2D) barcode systems, PDF417, is set up to identify the storage spaces and the stocks such that the picker can use a notebook with barcode reader to diagram the picking routes and automatic capture the data of picking parts. That makes the picking tasks much easier as it does not rely on the dedicated picker. A WEB-based information system is constructed to exchange the related messages. The purchasing orders and shipping lists are formed as XML/EDI formats and interchanged through the internet; and internal data are transacted via intranet under a client server system. By using the presented approaches, data transaction will be more accurate and real-timed. Moreover, warehouse spaces are used flexibly and efficiently, logistics costs are reduced, and services for customers are responded to quickly.

Application of the multi-agent approach in just-in-time production control system

Although the computerised information system is conventionally used in production control, applying a manual-driven approach and improper logistics assignments typically lead to lower operating efficiency and a slower customer service response time. This study presents an experimental multi-agent system mobile enterprise information portal (MEIP), developed for real-time production controlling across the intra-/inter-organisational supply system. A new formalism called tri-base model of the multi-agent communication/negotiation mechanism is employed to simulate the just-in-time (JIT) control manufacturing system. Several novel technical devices such as mobile agent system, two-dimensional (2D) barcode system, etc., are used to establish the real-time data capture and communication system. The findings of the case study indicate that the experimental multi-agent system can respond to the status of the production line in real time. This can help the production controller making an effect decision.

Enhancing the performance of healthcare services using a ZigBee-based mobile monitoring system

This study focuses on the method of real-time data capturing and responding to the in-bed patients. A smart bed-monitoring application using a ZigBee sensor network was developed and implemented to enable the physician and the caregiver to access patient data so that they can respond instantly to any irregularity in the condition of in-bed patients. System functions include real-time system status sensing and data collection, intelligent event tracing and ad hoc response mechanisms. The aim is to give both patient and caregivers better control of health care, reducing the burden on caregivers as well as reducing emergent occurrences.

The design of a fuzzy system shell using a database approach

This study presented a prototype of fuzzy system shell called FuzzyAccess. Using Microsoft Access database as a developing tools, the proposed system provided a friendly interface for user self-building a fuzzy system. A novice who has no programming-knowledge can also self-define a new fuzzy project. The main contributions of the proposed system were that using SQL method to search the candidate rules in rule evaluation stage and providing an integrated tuning interface for system adjustment. The SQL method can significantly reduce the search time in rule evaluation. The integrated tuning interface can assist user quickly inspecting the influence among different system parameters adjustment and reducing the system development time.

A Data Simulator for ZigBee-Base Wireless Sensor Network System

This paper presents a data simulator used to generate the test data of a specified instrument. The aim is focused on helping the user to quickly establish a wireless sensor network system. The proposed system includes a system simulator, an instrument definition module, and a network monitor module. System functions include network parameter setting, real-time system status sensing and data collecting. Applying the proposed model user can easily define the specifications of the corresponding digital instrument and then simulates the instrument in a PC. The proposed system enables user to quickly test the established wireless sensor network (WSN) system without installing the practical instruments.

An Intelligent Monitoring System Using a ZigBee-Base Sensor Network

This paper presents an intelligent monitoring system based on a ZigBee-base wireless sensor network. The proposed system includes a sensor network configuration module, an expert system shell, and an event-condition-action (ECA) engine. The sensor network configuration module is used to configure the working properties of the ZigBee components and set up the monitoring network. The expert system shell enables users to define the related events occurred at system running, the threshold of working conditions for triggering the corresponding events, and the required commands for fitting the system. The ECA engine is used to monitor the system and provide a suitable command for system fitting in a specified event being fired. The proposed system enables user to quickly establish a wireless sensor network system without well-experienced knowledge about the wireless sensor network and the expert system.