• Journal of Intelligence and Information Systems
• /
• v.3 no.2
• /
• pp.33-55
• /
• 1997

A data model is a diagram that describes the properties of different categories of data and the associations among them within a business or information system. In spite of its importance and usefulness, data modeling activity requires not only a lot of time and effort but also extensive experience and expertise. The data models for similar business areas are analogous to one another. Therefore, it is reasonable to reuse the already-developed data models if the target business area is similar to what we have already analyzed before. In this research, we develop a case-based reasoning system for data model reuse, which we shall call CB-DM Reuser (Case-Based Data Model Reuser). CB-DM Reuse consists of four subsystems : the graphic user interface to interact with end user, the data model management system to build new data model, the case base to store the past data models, and the knowledge base to store data modeling and data model reusing knowledge. We present the functionality of CB-DM Reuser and show how it works on real-life a, pp.ication.

• Journal of the Institute of Convergence Signal Processing
• /
• v.12 no.2
• /
• pp.119-127
• /
• 2011

The paper surveys various analytical models for IEEE 802.11 medium access control protocols and critically discusses recent issues developing in wireless mobile ad hoc networks and their MACs. The surveyed MAC protocols include the standard IEEE 802.11 MAC suites such as IEEE 802.11 DCF, IEEE 802.11 PCF, IEEE 802.11e EDCA, and IEEE 802.11 ad hoc mode; and also the newer, de facto MAC protocols. We study the analytic models of the standard MAC suites followed by the newer analytic models that have been published in recent years. Also, the paper tries to include most of current literatures discussing analytic modeling of MAC in conjunction to some critical issues such as contention among ad hoc nodes, hidden terminal problems, and real-time service support.

• International Journal of Internet, Broadcasting and Communication
• /
• v.16 no.1
• /
• pp.176-181
• /
• 2024

The desktop-level 3D printing machines makes it easier for independent designers to produce collectible models. Desktop 3D printers that use FDM (Fused Deposition Modeling) technology usually use a minimum nozzle diameter of 0.4mm. When using FDM printers to make Gunpla models, Thin slice structures are prone to slicing errors, which lead to deformation of printed objects and reduction in structural strength. This paper aims to analyze the printing model that produces errors, control a single variable among the three variables of slice layer height, slice wall thickness and filament type for comparative testing, and find a way to avoid gaps. To provide assistance for using FDM printers to build models containing thin-walled structures.

• Journal of the Microelectronics and Packaging Society
• /
• v.20 no.4
• /
• pp.75-79
• /
• 2013

A power distribution network (PDN) is a network that provides connection between the voltage source supply and the power/ground terminals of a microprocessor chip. It consists of a voltage regulator module, a printed circuit board, a package substrate, a microprocessor chip as well as decoupling capacitors. For power integrity analysis, the board and package layouts have to be transformed into an electrical network of resistor, inductor and capacitor components which may be expressed using the S-parameters models. This modeling process generally takes from several hours up to a few days for a complete board or package layout. When the board and package layouts change, they need to be re-extracted and the S-parameters models also need to be re-generated for power integrity assessment. This not only consumes a lot of resources such as time and manpower, the task of PDN modeling is also tedious and mundane. In this paper, a block-based PDN modeling is proposed. Here, the board or package layout is partitioned into sub-blocks and each of them is modeled independently. In the event of a change in power rails routing, only the affected sub-blocks will be reextracted and re-modeled. Simulation results show that the proposed block-based PDN modeling not only can save at least 75% of processing time but it can, at the same time, keep the modeling accuracy on par with the traditional PDN modeling methodology.

• Journal of the Korea Computer Graphics Society
• /
• v.3 no.1
• /
• pp.17-22
• /
• 1997

This paper presents a new modeling technique to reconstruct road environments. The reconstruction algorithm for road environments consists of three parts - reconstructing 3D models of architectures in road environments, editing and creating road models, and modeling auxiliary objects. Different modeling technique is applied to each of these three parts according to properties objects to be modeled contain. In this reconstruction system, modified Photogrammetric Modeling techique is used, of which the user interface is more convenient, and in which constraints of road environments are considered. These improvements make this road environment reconstruction system much simpler and easier to use compared with Photogrammetric Modeling technique[1, 2].

• Journal of Korean Institute of Industrial Engineers
• /
• v.36 no.3
• /
• pp.176-185
• /
• 2010

As long as the information systems are spread out, various efforts are being attempted to get the effective results by the system. As a result, a new management strategy has been appeared, referred to as "collaboration", and it is necessary to use a right methodology for modeling collaborative processes accordingly. Even though many modeling methodologies such as IDEF3, Petri-Nets, UML, and ARIS have been widely used for modeling processes, they are inadequate for clearly representing collaborative processes. Some researchers, therefore, have suggested new modeling methodologies for describing collaborative processes including CPM (collaborative process modeling). In this paper, we introduce an extended version of CPM method (i.e., exCPM) as a tool for modeling collaborative works after analyzing advantages and disadvantages of aforementioned methodologies. One of distinct characteristics of exCPM is that model verification is possible by transforming the exCPM models into Petri-Nets models. We also demonstrate transformation of an exCPM model in this paper with case studies for model verification.

• International Journal of Computer Science & Network Security
• /
• v.21 no.9
• /
• pp.247-260
• /
• 2021

Data modeling is a process of developing a model to design and develop a data system that supports an organization's various business processes. A conceptual data model represents a technology-independent specification of structure of data to be stored within a database. The model aims to provide richer expressiveness and incorporate a set of semantics to (a) support the design, control, and integrity parts of the data stored in data management structures and (b) coordinate the viewing of connections and ideas on a database. The described structure of the data is often represented in an entity–relationship (ER) model, which was one of the first data-modeling techniques and is likely to continue to be a popular way of characterizing entity classes, attributes, and relationships. This paper attempts to examine the basic ER modeling notions in order to analyze the concepts to which they refer as well as ways to represent them. In such a mission, we apply a new modeling methodology (thinging machine; TM) to ER in terms of its fundamental building constructs, representation entities, relationships, and attributes. The goal of this venture is to further the understanding of data models and enrich their semantics. Three specific contributions to modeling in this context are incorporated: (a) using the TM model's five generic actions to inject processing in the ER structure; (b) relating the single ontological element of TM modeling (i.e., a thing/machine or thimac) to ER entities and relationships; and (c) proposing a high-level integrated, extended ER model that includes structural and time-oriented notions (e.g., events or behavior).

• Journal of The Korean Association For Science Education
• /
• v.37 no.5
• /
• pp.859-877
• /
• 2017

The purpose of this study is to probe secondary science teachers' perception on scientific models and modeling. A total of 50 experienced science teachers were surveyed with 10 open-ended questions about several aspects of models and modeling: definition, examples, purpose, multiplicity, changeability, design/construction, evaluation and beliefs in the use of models and modeling as a teaching tool. The analysis of the data shows the following results: 1) understanding of models and modeling held by a majority of experienced secondary science teachers was far from that of experts as they concentrated on a model's superficial, representative, and visual functions, 2) when it comes to their view toward the use of a model, a model does not remain in the stage of 'doing science' but in the stage of being a subsidiary teaching tool for the teacher's explaining and the students' understanding of scientific concepts, 3) the subjects they majored in made meaningful differences in their contextual understanding of models and modeling, 4) though most of the teachers acknowledged the importance of teaching about models and modeling, even a lot of them showed a negative position toward the opinion that they are willing to apply modeling to their classes. Implications of the results were discussed in terms of intervention in order to enhance secondary science teachers' understanding and pedagogical content knowledge of models and modeling.

• Journal of Environmental Impact Assessment
• /
• v.19 no.3
• /
• pp.307-314
• /
• 2010

Brebbia's model has been analyzed to develop the appropriate waterworks management system in Korea, and compared with the conventional models such as EPANET, WaterCad, and InfoWorks. The hydraulic theory of the models was analyzed. Each model's numerical techniques, required parameters, input data and operational methodologies, restrictions, practical applicability and other aspects were investigated. In order to check the validity of Brebbia model, the comparative analysis with EPANET, WaterCAD, and InfoWorks models was performed for linear and nonlinear cases. To find out advantages and disadvantages of each model, the modeling was performed for a simple network and for more complicated A city waterworks system, and the three models applicability was examined. Finally, optimal modeling technique and a model suitable for the use in Korea was suggested, and the problems related to present projects of waterworks management system in Korea were analyzed.

• ETRI Journal
• /
• v.32 no.5
• /
• pp.810-818
• /
• 2010

This paper presents a new framework for integrating untranscribed spoken content into the acoustic training of an automatic speech recognition system. Untranscribed spoken content plays a very important role for under-resourced languages because the production of manually transcribed speech databases still represents a very expensive and time-consuming task. We proposed two new methods as part of the training framework. The first method focuses on combining initial acoustic models using a data-driven metric. The second method proposes an improved acoustic training procedure based on unsupervised transcriptions, in which word endings were modified by broad phonetic classes. The training framework was applied to baseline acoustic models using untranscribed spoken content from parliamentary debates. We include three types of acoustic models in the evaluation: baseline, reference content, and framework content models. The best overall result of 18.02% word error rate was achieved with the third type. This result demonstrates statistically significant improvement over the baseline and reference acoustic models.