• Journal of Computing Science and Engineering
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• v.9 no.3
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• pp.155-162
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• 2015

The last decade has seen a rapid growth in the use of mobile devices all over the world. With an increasing use of mobile devices, mobile applications are becoming more diverse and complex, demanding more computational resources. However, mobile devices are typically resource-limited (i.e., a slower-speed CPU, a smaller memory) due to a variety of reasons. Mobile users will be capable of running applications with heavy computation if they can offload some of their computations to other places, such as a desktop or server machines. However, mobile users are typically subject to dynamically changing network environments, particularly, due to user mobility. This makes it hard to choose good offloading decisions in mobile environments. In general, users' mobility can provide some hints for upcoming changes to network environments. Motivated by this, we propose a mobility model of each individual user taking advantage of the regularity of his/her mobility pattern, and develop an offloading decision-making technique based on the mobility model. We evaluate our technique through trace-based simulation with real log data traces from 14 Android users. Our evaluation results show that the proposed technique can help boost the performance of mobile devices in terms of response time and energy consumption, when users are highly mobile.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.288-291
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• 2008

Recently, the importance and necessity of engineering analysis has shown a steady growth. However, researchers working in small and medium enterprises know little about the usefulness of engineering analysis and suffer from lack of technical knowledge. Axial fan is air fluid machinery in various fields of industry such as automobile, electric appliance, and heavy machinery. It is also a time and budget consuming equipment to develop the axial fan through physical experiments. In order to overcome this problem, we have designed and developed a web-base automated simulator for axial fan's fluid analysis using supercomputer. Automated simulator means that all of processes for engineering analysis including pre-process, solving, and post-process can be performed automatically without user intervention after transferring fan model(CAD files) made by user. After executing the simulator with some parameters, user can receive the report including pressure P and flow rate Q. In this paper, we introduce the architecture of our easy and efficient automated engineering analysis simulator, related techniques and result of development.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.35-41
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• 2013

Nowadays, automated modeling system for steel margin based on interactive user interface has been developed and applied to the production design stage. The system could increase design efficiency and minimize human error owing to recent CAD technique. However, there has been no approach to the pre-nesting design stage at all in early modeling process especially where ship model should be handled at more than two design stages using AVEVA Marine. A designer of the design stage needs artificial intelligence system beyond modeling automation when 3D model must be prepared in early modeling process using AVEVA Marine because they have focused on 2D nesting traditionally. In addition, they have a hard time figuring out the model prepared in previous design stage and modifying the model for steel purchase size in early modeling process. In this paper, artificial intelligence modeling system for automated application of steel margin in early modeling process using AVEVA Marine is developed in order to apply to the pre-nesting design stage that can detect effective segments before a calculation to find if a segment locates near block butt boundaries by filtering noise segments among lines, curves and surface intersections based on IT big data analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.261-272
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• 2013

LRT(Light Rail Transit), which has many merits compared with Heavy Rail Transit, is an effective public transport. Therefore, many local governments are pushing ahead with LRT. Busan had already adopted LRT(AGT)s like Busan Subway Line 4(Bansong Route) and Busan Gimhae Light Rail Transit(BGLRT) domestically for the first time. This study analyzes user satisfaction about the services of adopted LRTs and set right priorities of remeding their shortcomings from the user's perspective. In this paper, we surveyed safety consciousness and services satisfaction of LRT(BGLRT) users, and made two User Satisfaction Models of each LRT(BGLRT and Bansong Route) using Structural Equation Model. With established User Satisfaction Models(BGLRT Model and Bansong Route Model), we compared BGLRT and Bansong Route. Finally we found the measures and priorities for the improvements of LRT's services in the aspect of LRT users.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.537-540
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• 1992

This paper presents Samsung CNC (Computer Numerical Controller) system with an intel 80486/487 as the main CPU and a 32 bit floating point DSP(Digital Signal Processor) TMS320C30 as the motion control CPU. The Samsung CNC system diverse user-frienly characteristics such as multi-tasking, powerful menu system, internal PLC system, and 2/3 dimensional graphics in wire and solid mode. The main CPU executes central processing program, user interface program, interpreter, BMI, etc while the motion control CPU carries out some interpolations, acceleration/deceleration, and PID control algorithm with feedforward terms. Complex interpolations except linear and circular ones are performed on the main control CPU. The experimental results for the circular interpolation under linear acceleration/deceleration shows that the proposed CNC system can be widely used in controlling machining centers with good machining accuracy.

• The Research Journal of the Costume Culture
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• v.13 no.5 s.58
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• pp.819-832
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• 2005

The purpose of the study was to examine female college students' credit card usage characteristics and to investigate differences in buying propensity of clothing including impulse buying, consciousness, and conspicuous consumption among their buyer groups according to credit card use and personal characteristics. The questionnaires were administered to female college students in Seoul. The total of 588 questionnaires were collected and statistically analyzed by descriptive statistics, factor analysis, Analysis of Variance (ANOVA), and Duncan's test. Female college students' arrear as well as credit card use have been increasing, and they tend to purchase low price clothing item using credit card. Buying propensity was classified into three factors. There were differences in buying propensity of clothing including impulse buying, fashion consciousness, and conspicuous consumption among buyer groups according to the credit card use and personal characteristics. Students who have credit card and arrear experience, are heavy credit user, and purchase more clothing showed high impulse buying propensity. Students who purchase more clothing monthly with credit card were more fashion-conscious. Students who have credit card, are heavy credit user, and purchase more clothing showed high conspicuous consumption propensity. Implications and future research directions were discussed.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1257-1259
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• 1996

In this paper, we introduce an integrated communication and control system(ICCS) for control of a crane. The system is integrated with a compasite technique as a network interfacing, a user interfacing and a system control for continuous process like as a container crane. The field-bus(Profibus) network module is used to interconnect each input/output module with main control unit. The MMI system for user interfacing is integrated with an ODBC-based data management tool and IECl131-based control logic design tool(Soft-Logic Designer:SLD). The each programmed control task in the main Controller is executed using a petri-net based scheduler.

• IE interfaces
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• v.25 no.1
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• pp.1-12
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• 2012

The challenges facing manufacturing companies today span across the industry, independent of company size or product. Especially, big manufacturers must overcome these challenges, and information technology (IT) collaboration with small and medium enterprises (SMEs) will play a major role in this effort. In this research, the strategy and way to promote IT collaboration between SMEs and large firms in heavy industries are proposed. A pre-consultation was performed to derive the strategy and way for the collaboration, and an IT collaboration system was developed reflection the results of pre-consultation. The IT collaboration system consists of two parts. One is ERP based on BPM for SMEs to standardize and visualize the entire business process from order placement to release. This system also provides their parent company with visibility into the status of orders and user can easily access the system on the web at a low price through cloud computing service. The other is interface part for data changes between large firms and SMEs. Thus far, this paper demonstrates the importance of strategy for the collaboration, and the applicability of IT collaboration system to elevate the speed and efficiency of business.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.1
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• pp.83-101
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• 2016

This paper suggests an event-based scenario manager capable of creating and editing a scenario for shipbuilding process simulation based on multibody dynamics. To configure various situation in shipyards and easily connect with multibody dynamics, the proposed method has two main concepts: an Actor and an Action List. The Actor represents the anatomic unit of action in the multibody dynamics and can be connected to a specific component of the dynamics kernel such as the body and joint. The user can make a scenario up by combining the actors. The Action List contains information for arranging and executing the actors. Since the shipbuilding process is a kind of event-based sequence, all simulation models were configured using Discrete EVent System Specification (DEVS) formalism. The proposed method was applied to simulations of various operations in shipyards such as lifting and erection of a block and heavy load lifting operation using multiple cranes.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.407-417
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• 2015

For the more accurate prediction on manoeuvring performance of a ship at initial design phase, bare hull manoeuvring coefficients were estimated by RANS(Reynolds Averaged Navier-Stokes) based virtual captive model tests. Hydrodynamic forces and moment acting on the hull during static drift and harmonic oscillatory motions were computed with a commercial RANS code STAR-CCM+. Automatic and consistent mesh generation could be implemented by using macro functions of the code and user dependency could be greatly reduced. Computed forces and moments on KCS and KVLCC 1&2 were compared with the corresponding measurements from PMM(Planar Motion Mechanism) tests. Quite good agreement can be observed between the CFD and EFD results. Manoeuvring coefficients and IMO standard manoeuvres estimated from the computed data also showed reasonable agreement with those from the experimental data. Based on these results, we could confirm that the developed virtual captive manoeuvring model test process could be applied to evaluate manoeuvrability of a ship at the initial hull design phase.