• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.7A
• /
• pp.1090-1098
• /
• 1999

In this paper ERP-4 viterbi decoder for magnetic disk read channel is designed. The viterbi decoder consists of ACS circuit, path memory circuit, minimum detection circuit, and output selection circuit. In the viterbi decoder the number of state is reduced from 8 to 6 using (1,7) RLL codes and modulo comparison based on 2's complement arithmetic is applied to handle overflow problem of ACS module. Also to determine the correct symbol values in nonconvergent condition of path memory, pipelined minimum detector which determines path with minimum state metric is used. The EPR-4 viterbi decoder is designed using 0.35${\mu}{\textrm}{m}$ CMOS technology and consists of about 15,300 transistors and has 250 Mbps data rates under 3.3 volts.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.14 no.5
• /
• pp.1138-1146
• /
• 1990

A knowledge-based expert system has been developed implementing the ambiguous process of conceptual design of flywheels in earlier design stage to assist the selection of proper flywheel types and dimensions. Knowledge for the flywheel design consists of the rules for conventional as well as super flywheels and other informations required for the design process. Those knowledges were extracted from literatures and some experts in the field. With these knowledges, an integrated knowledge based expert system was developed to help users with informations and facilities to design flywheels interactively using a commercial package of knowledge-based system called INSIGHT2 of backward chaining and proprietary package of forward chaining written in LISP language. The developed system consists of the knowledge base part and calculation park : the first one consists of main module and user level modules and the other one is to assist in analyzing the stress distribution in the flywheels and deciding the flywheel dimensions and specifications for various types of flywheels using proper data bases and graphic facilities. With this flywheel design software, several examples were tried generating acceptable design results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.183-186
• /
• 2006

It is studied the implementation possibility of some encryption algorithms which meet the performance requirements in the smart card used in the TETRA system End-to-End Encryption. It is measured the operation time of the algorithm in the smart card which has 32 bit smart card controller made by Samsung Electronics. The algorithms used in the performance comparison are AES, ARIA, 3DES, SEED, IDEA which are the domestic or international standards. The input and output time of the smart card are measured using the smart card protocol analyzer. The pure algorithm operation time is calculated by the repeated algorithm operations. This measurement results can be used as the criteria for the selection of algorithm which will be used in the TETRA End-to-End encryption system. The algorithm which has better performance can be used for the implementation of additional functions in the smart lard, because of the enough time margin.

• Journal of the Institute of Convergence Signal Processing
• /
• v.10 no.4
• /
• pp.233-238
• /
• 2009

In this paper, we propose the methods to select the stable region for the detect region which is required in the system used the face to the ROI in the auto-focus digital camera. this method regards the face region as the ROI in the progressive input frame and focusing the region in the mobile camera embeded ISP module automatically. The learning algorithm to detect the face is the Adaboost algorithm. we proposed the method to detect the slanted face not participate in the train process and postprocessing method for the results of detection, and then we proposed the stabilization method to sustain the region not shake for the region. we estimated the capability for the stabilization algorithm using the RMS between the trajectory and regression curve.

• The KIPS Transactions:PartD
• /
• v.16D no.1
• /
• pp.93-104
• /
• 2009

Modular implementation of a feature is a first step toward feature-oriented product line engineering, which develops and then utilizes core assets to configure products in terms of features. Aspect-oriented programming provides effective mechanisms for improving the modularity of feature implementations. However, as features in general are not independent of each other, changes in the implementation of one feature may cause changes to or side effects in the implementation of other features. Moreover, since the time at which a feature is incorporated into products, called feature binding time, may be various from compile time through load time to run time, a feature may have to be implemented differently depending on when the feature is bound into a product. To make each feature implementation module as independent as possible, this paper proposes aspectual implementation patterns that can effectively separate feature dependencies as well as feature binding time from feature implementation modules. These patterns enable flexible composition of feature implementation modules without affecting other modules according to feature selection. The approaches are demonstrated and evaluated based on a product line of scientific calculator applications.

• Journal of the Korea Convergence Society
• /
• v.13 no.3
• /
• pp.33-41
• /
• 2022

In this article, we proposed to predict natural gas (NG) leakage levels through feature selection based on a factor analysis (FA) of the integrating the Korean Meteorological Agency data and natural gas leakage data for considering complex factors. The paper has been divided into three modules. First, we filled missing data based on the linear interpolation method on the integrated data set, and selected essential features using FA with OrdinalEncoder (OE)-based normalization. The dataset is labeled by K-means clustering. The final module uses four algorithms, K-nearest neighbors (KNN), decision tree (DT), random forest (RF), Naive Bayes (NB), to predict gas leakage levels. The proposed method is evaluated by the accuracy, area under the ROC curve (AUC), and mean standard error (MSE). The test results indicate that the OrdinalEncoder-Factor analysis (OE-F)-based classification method has improved successfully. Moreover, OE-F-based KNN (OE-F-KNN) showed the best performance by giving 95.20% accuracy, an AUC of 96.13%, and an MSE of 0.031.

• Journal of Practical Engineering Education
• /
• v.15 no.3
• /
• pp.571-580
• /
• 2023

With the advent of the Fourth Industrial Revolution, there is an increasing demand for interdisciplinary studies in the realm of university education. Accordingly, this study sought to explore learners' perceived expectation factors for a modular curriculum, one of the primary strategies for curriculum revision in interdisciplinary departments, by applying the Expectation Theory. Learners' perceptions were measured pre and post during the second semester of 2022. The results confirmed that among the expectation factors, the selection factor significantly decreased after the course compared to before. Changes in the understanding and perceived difficulty level of tool utilization within the course may have influenced these results. The significance of this study lies in providing direction for curriculum revisions in interdisciplinary departments by analyzing learners' perceptions of the modular curriculum. Specifically, curriculum design should focus on reducing difficulties and cognitive burdens associated with educational tool utilization. Furthermore, considering that students' prior experience and understanding of educational tools can impact educational outcomes, it is crucial to factor these elements when designing a modular curriculum.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.3
• /
• pp.143-155
• /
• 2016

Recently, the interest on applying AVM(Around View Monitoring) systems in construction equipments have been increasing due to the demand for better control, work efficiency and safety. Most of the existing AVM systems have been developed focusing on the application in automobiles and only several AVM systems have been developed for construction equipments. However, the original technology of AVM remained the same as in the automobiles that failed to consider the main properties of construction equipments and suggest appropriate range of AVM display (Top-view). Therefore, the purpose of this study is to suggest a pilot type of AVM system for construction equipment. Accordingly, literature review, deduction of main consideration factors, selection of sensors, system design, algorithm development of a pilot type of AVM system for construction equipment have been conducted. A laboratory experiment has also been conducted for the deduction of further improvements. As a result, a minimum image refresh rate of 20 fps has been achieved that clearly reflects the actual situation of the equipment and also, the actual motions of Boom, Arm, Bucket have been displayed appropriately on the AVM system based on the angle data collected by sensors. However, the experiment results have also shown that the following tasks still remain for future work: 1)Improvement of AVM image interpolation, 2)Development of calibration module for variety construction equipment.

• Journal of the Society of Disaster Information
• /
• v.14 no.2
• /
• pp.130-140
• /
• 2018

Purpose: In this paper, we propose a design technique for the safety characterization grounding in the construction of the photovoltaic power generation complex which can be useful and useful as an alternative power energy source in our society. In other words, we will introduce the application of safety grounding for each application, which can improve and optimize the reliability of the internal grid from the cell module to the electric room in the photovoltaic power generation complex. Method: We analyze the earth resistivity of the soil in the solar power plant and use the computer program (CDEGS) to analyze the contact voltage and stratospheric voltage causing the electric shock, and propose the calculation and calculation method of the safety ground. In addition, we will discuss the importance of semi-permanent ground electrode selection in consideration of soil environment. Results: We could obtain the maximum and minimum value of ground resistivity for each of the three areas of the data measured by the Wenner 4 - electrode method. The measured data was substituted into the basic equation and calculated with a MATLAB computer program. That is, it can be determined that the thickness of the minimum resistance value is the most favorable soil environment for installing the ground electrode. Conclusion: Through this study, we propose a grounding system design method that can suppress the potential rise on the ground surface in the inner grid of solar power plant according to each case. However, the development of smart devices capable of accumulating big data and a monitoring system capable of real-time monitoring of seismic changes in earth resistances and grounding systems should be further studied.

• Journal of KIISE:Software and Applications
• /
• v.31 no.8
• /
• pp.1027-1042
• /
• 2004

A Software Component is a module that is reused among a lot of projects, systems, and companies rather than a single application. Components can be reused in various systems if they provide not only the common functionalities required in many applications but also the diverse aspects to be customized for being suitable for customers' demands. From the development phase, components should be designed and developed considering the variable aspects they have for convenient customization. Easily customized components can be frequently reused in lots of applications. In the literature, there are some modeling and customizing techniques. But they suggested only conceptual or basic methods based on Object-Oriented. And the practical instructions for reusing component were not provided sufficiently. Moreover, there are few techniques that consider the proper variability types components have. Thus, those techniques are not appropriate for applying to black box component completely developed and released. In this paper, we classify variabilities that components have in functional aspect into two categories. The one is logic variability, and the other is workflow variability. For each classified variability, we propose the three kind of modeling techniques, which are selection, plug in and externalization. Also detailed instructions for practical design and application are provided.