Dongmin Shin

A product platform concept development method

Quality function deployment (QFD) was initially developed to aid in designing a quality product by interconnecting customer needs in a market segment with technical requirements (TRs). It can assist in improving product quality but does not have a function to examine TRs across the major market segments serviced by a companys product lines and to aid in developing the modular product platform concept. In this paper, we present a product platform concept development method that aids in developing the modular platform concept as well as improving an understanding of product family design. This method is conducted in three steps. The first step is to identify platform TRs from QFD by classifying TRs into either constant or variant TRs. The second step is to construct the platform planning chart, which is to identify the relationship between basic components and TRs and calculate degree of variety (DV) of components. Finally, the platform concept is explored on design structure matrix with DV. This paper uses an electric razor example to illustrate the proposed method.

A formal control-theoretic model of a human–automation interactive manufacturing system control

This paper describes a human–automation interactive manufacturing system and presents a formal model for describing and controlling the system. The model presented in this paper considers a system from two perspectives: structural and operational perspectives. Human and an automated controller are considered agents that cooperate to achieve given goals by executing assigned tasks. A human–automation interaction is described with a particular communication model between two agents that exchanges messages. A system control schema and human tasks are modelled separately and then integrated in a formal manner using a modified communicating finite state machine framework. An interface model that coordinates the message exchanges between two agents is then introduced. An automated shop floor control system with a human material handler is modelled with the proposed framework and a simple illustrative example is provided.

Exploring the Relationship between Keywords and Feed Elements in Blog Post Search

Blogs are increasingly accepted as a useful means to proliferate a variety of information on the web. As the popularity of blogs grows rapidly, a number of blog search engines have appeared recently to help users access and discover blog posts efficiently. Nevertheless, existing approaches tend to focus on ranking the blog posts according to their recency or popularity only, leaving the problem of retrieving more topic relevant posts to a user’s query largely unexplored. In this paper, we present a novel blog ranking framework, called PTRank, that improves search quality by taking account of relevance feedback from users as well as various information available from RSS feeds. A neural network method is employed to learn ranking functions that provide a relevance score between a keyword and a blog post. Extensive experiments on real blog data have been conducted to validate the proposed ranking framework for blog post search, and the results indicate that PTRank performs significantly better than the existing popular approach.

Using finite state automata (FSA) for formal modelling of affordances in human-machine cooperative manufacturing systems

Modelling complex systems poses significant challenges on how one represents the system components and interactions among them. In order to provide a systematic approach to represent human participation as a part of a dynamic system, this paper presents a formal automata model of human-machine cooperative systems that incorporates human capabilities with respect to system conditions. Specifically, we propose a control model for human-involved shop floor systems based on discrete event-based systems (DES) and an environmental concept known as an affordance. When modelling human-involved systems where a human operator is considered a crucial system component, it is necessary to analyse the model complexity that increases significantly due to a humans behavioural patterns. From the perspective of the temporal and physical state domains a human operators behaviour is usually limited by attention and resource constraints. We investigate these limitations and map them into constrained system affordances, and then construct a formal human-machine cooperative model based on the finite state automaton (FSA) model. The proposed model can provide a framework to combine human activities into systems operations in consideration of humans effectivities and system affordances. A detailed application example is provided to illustrate that the proposed model can effectively be applied to manufacturing control systems.

Formal model of human material-handling tasks for control of manufacturing systems

To achieve an effective integration framework for manufacturing systems, a formal model of a system is highly desired. In spite of significant work on automated manufacturing systems, human operators still play a critical role in virtually every system, especially for material-handling processes. To build a model for control and analysis of a system where a human operator is integrated, a formal functional specification of a human material handler (MH) is presented in a hierarchical framework. Two types of human operational errors associated with material-handling tasks are also classified and discussed. A shop floor control example is provided to illustrate the proposed modeling framework

An investigation of a human material handler on part flow in automated manufacturing systems

This paper presents a formal approach to resolve an important question concerning changes in the control of computerized manufacturing systems when a human operator is involved as a task-performing agent. It requires building a model of human functional specifications used in executing tasks and integrating it into a control scheme for the model. More importantly, analysis of control complexity needs to be conducted to build an effective control mechanism. In this paper, a human material handler is considered, and an assessment of part flow complexity affected by human tasks in a highly automated manufacturing system is presented. For this purpose, a formal model of human task-performing processes is proposed in terms of a part and location(s) of a task. A classification for human material handling tasks is presented based on the proposed model. Furthermore, human errors and the impact of human errors on part flow are considered. Part flow complexity of a manufacturing system from the control perspective is then investigated in terms of the human tasks and errors. A shop floor control example where a human operator performs material handling tasks is provided to illustrate the proposed model.

Completeness and regularity of generalized fuzzy graphs

Fuzzy graphs are the backbone of many real systems like networks, image, scheduling, etc. But, due to some restriction on edges, fuzzy graphs are limited to represent for some systems. Generalized fuzzy graphs are appropriate to avoid such restrictions. In this study generalized fuzzy graphs are introduced. In this study, matrix representation of generalized fuzzy graphs is described. Completeness and regularity are two important parameters of graph theory. Here, regular and complete generalized fuzzy graphs are introduced. Some properties of them are discussed. After that, effective regular graphs are exemplified.

Controllable lead time, service level constraint, and transportation discounts in a continuous review inventory model

This paper studies two models based on the distribution of lead time demand. The first model assumes a normally distributed lead time demand and the second assumes that there is no specific distribution for lead time demand, but it is with known mean and standard deviation. The continuous-review inventory model is used for both cases. Transportation cost is dependent on the ordered quantity i . e ., how much quantity buyer orders for delivery, based on that, a transportation discount is used to reduce the total cost. Service level constraint is included in this model to avoid backorder cost. Two efficient lemmas are established to obtain the optimum solution of the model. The expected value of additional information (EVAI) is calculated to show the excess amount needed for the distribution free case. Some numerical examples and sensitivity analysis are given to illustrate the model.

FlowWiki: A wiki based platform for ad hoc collaborative workflows

Traditional workflow management systems provide rich capabilities for designing, executing, and monitoring well-defined collaborative processes. Yet, for many occasions of collaboration, we do not often have sufficient information about who will participate, what activities people will carry out, and how the entire workflow will change. Accordingly, the problem of managing flexible workflows has been receiving increasing attention during the last decade. This paper presents a novel approach by which collaborative workflows can be configured independently as needed by participants and managed in an ad hoc way. Motivated by the emerging paradigm of collective intelligence, the proposed platform, named FlowWiki, provides a set of useful mechanisms to enable dynamic collaborations without requiring prescribed collaboration model. FlowWiki is an extension of conventional wiki system, and it aims for flexibly managing collaborative workflows by allowing on-demand workflow configuration and event-driven interactions.

Ergonomic hand tool and desk and chair development process.

This paper suggests a practical and simple process consisting of 8 stages: needs assessment, ergonomics guidelines, anthropometry, brainstorming and idea sketch, preliminary model, drafting and rendering, working prototype, and user trials. The feasibility of this process was verified with the development of a modified clamping hand tool and a new student desk and chair. The case studies showed how design difficulties were overcome by integrating ergonomics guidelines in the process.