• The Journal of Industrial Distribution & Business
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• v.9 no.2
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• pp.47-55
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• 2018

Purpose - To meet the needs of various customers in an uncertain market environment, many companies use product modularization strategies. Modularization of a product means that one product consists of several components and that the type of product can be changed according to the combination of components. The greatest feature of modularity is that changes in one component do not significantly affect the physical changes in the other component to which they are connected. Modularization of products is recognized as a very important strategy to reflect increasingly complicated customer requirements to products and respond to the needs of various markets. Many studies have been made in connection with the concept of mass customer satisfaction. There are many prior studies that modularization of such products positively affects the operational performance (manufacturing cost, fast delivery, etc.) and innovation of the product. However, excessive modularization has been found to have a negative effect on this performance. However, there are very few studies on the nonlinear relationship between product modularization and customer satisfaction. Supplementing these academically insufficient parts is very necessary when considering the current market environment. Research design, data, and methodology - In order to make up for the shortcomings of academic research in Korea, this study collects data through questionnaires in electronic, auto, and defense industry. This is because these industries are using modularity of products. based on lots of previous studies and information overload theory, we made two hypothesis and verify with empirical analysis. All 108 data were used. We used the R program and SPSS program for statistical verification. Results - As a result of the study, modularization of products showed positive relationship with customer satisfaction to a certain level. However, it has been found that when the modularization is over and beyond a certain level, there is a negative relationship with customer satisfaction. Conclusions - Excessive modularization of products can have a negative impact on customer satisfaction. This result can be understood as a result of human limited rationality due to information overload. Therefore, it is important for companies to apply appropriate modularity to product design.

• Journal of Korea Game Society
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• v.9 no.5
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• pp.53-61
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• 2009

Game industry, especially MMORPG (Massively Multiplayer Online Role Playing Game) has rapidly been expanding in these days. In this background, lots of online game security incidents have been increasing and getting more diversity. One of the most critical security incidents is 'Bots', mimics human player's playing behaviors. Bots performs the task without any manual works, it is considered unfair with other players. So most game companies try to block Bots by analyzing the packets between clients and servers. However this method can be easily attacked, because the packets are changeable when it is send to server. In this paper, we propose a Bots detection method by observing the playing patterns of game characters with data on server. In this method, Bots developers cannot handle the data, because it is working on server. Therefore Bots cannot avoid it and we can find Bots users more completely.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.3
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• pp.16-23
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• 2017

For most machine tools, it is necessary to remove chips and coolant oil because it they will continue to be created during the manufacture of workpieces. Existing products that are in use are installed and used as they reflect depending on the characteristics of each device separately. This study proposes a method to remove the security chip as well as developing an integrated system capable of reducing coolant damage. The Leverage AutoCAD and CATIA program was used for 2D and 3D design, shapes were identified by utilizing the KeyShot program, and the load and displacement analysis of the development apparatus was performed utilizing the ANSYS program. After the prototype underwent sufficient design review, the mixed oil separation device had a complete sensor control program using the LabVIEW program. The chip design process for transferring experiments and experiments on the mixed oil cooling device were developed for performance tests of the product. The final product resulted in an increase in space utilization during commercialization, reduced installation costs, and caused social effects such as pulmonary flow reduction, which, through the economic costs, reduces pollution, resulting in various benefits to the industry, such as deceased errors in the workplace decreases.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.104-109
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• 2020

Recently, vibration and noise have become an important issue in the auto industry. Asphalt vibration damping pads are used to reduce the noise and vibration of automobile bodies, and asphalt is used for many mass-produced parts due to its simple attachment process and low processing costs. In this study, the self-adhesion of asphalt pads using Joule heating was evaluated. To create the asphalt pad for the experiment, the asphalt pad was molded into a specific thickness by using SGACC material and rubber used in the vehicle body as a main component and a modified resin and filler. The SGACC material was 200 mm in length, 200 mm in width, and 0.7 mm in thickness. The asphalt pad was 200 mm in length, 100 mm in width, and 3 mm in thickness. The equipment was composed of a TR (Transformer) DC254kVA and a TC (Time controller) for a current of up to 20,000 A. The current for the Joule heating was set to 7.0 kA and a 3/1 cycle, for which the adhesion of the asphalt pad over the current flow time was evaluated.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.186-195
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• 2016

The finite element modeling of a ship for hull structural analysis on the basis of new harmonized common structural rules (CSR-H) is to be extended to the cargo holds in fore and after body of a ship. Unlike the parallel middle-body where the external and internal features of hull are equal along to the longitudinal direction of a ship, in fore and after body, the external and internal features of hull vary linearly or even irregularly in forms of a surface or a curve along to the longitudinal direction of a ship. Thus, it needs lots of design man-hours for the modeling for structural analysis. In order to save man-hours in initial structural design phase of a ship, the specified 3D CAD system has been adopted in shipbuilding industry. Through the interface between CAD and CAE (rule scantling and direct strength assessment), design man-hour in initial design phase can be saved even under the environment of CSR-H.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.205-210
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• 2015

The auto industry has significantly evolved to the extent that much attention is paid to M2M (Machine-to-Machine) communication. In M2M communication which was first used in meteorology, environment, logistics, national defense, agriculture and stockbreeding, devices automatically communicate and operate in accordance with varying situations. M2M system is applied to vehicles, specifically to device-to-device communication inside cars, vehicle-to-vehicle communication, communication between vehicles and traffic facilities and that between vehicles and surroundings. However, communication systems are characterized by potential intruders' attacks in transmission sections, which may cause serious safety problems if vehicles' operating system, control system and engine control parts are attacked. Thus, device-to-device secure communication has been actively researched. With a view to secure communication between vehicular devices, the present study drew on hash functions and complex mathematical formulae to design a protocol, which was then tested with Casper/FDR, a tool for formal verification of protocols. In brief, the proposed protocol proved to operate safely against a range of attacks and be effective in practical application.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1344-1368
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• 2007

The Advanced countries including Japan, USA and European countries are adopting automatic system(e.g., auto-measurement using CCD camera) for measuring pantograph sliding plate and wheel abrasion to minimize manpower for E.M.U(Electric Multiple Unit) inspection and maintenance as part of management rationalization of railroad Corporation since late 1980's. In Korea, as part of scheme of business rationalization, automatic system for measuring pantograph sliding plate and wheel abrasion started to draw industry attention since late 1990s, and the system started to be installed in newly built depots of Korea Railroad Corporation since 2002. This study hopefully provides the base for realizing business rationalization and applying the advanced technology developed by Korea, the country of powerful IT basis, to overseas railroad organizations by examining automatic system for measuring pantograph sliding plate abrasion using existing CCD cameras produced domestically and in foreign countries to study cases(organizations in Korea) for improvement of measurement, management and inspection of pantograph sliding plate abrasion using CCD cameras with new cutting-edge technology; and by applying the study result to railroad organizations in metropolitan areas in Korea.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.25-30
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• 2016

It is critical to forecast the maximum daily and monthly demand for power with as little error as possible for our industry and national economy. In general, long-term forecasting of power demand has been studied from both the consumer's perspective and an econometrics model in the form of a generalized linear model with predictors. Time series techniques are used for short-term forecasting with no predictors as predictors must be predicted prior to forecasting response variables and containing estimation errors during this process is inevitable. In previous researches, seasonal exponential smoothing method, SARMA (Seasonal Auto Regressive Moving Average) with consideration to weekly pattern Neuron-Fuzzy model, SVR (Support Vector Regression) model with predictors explored through machine learning, and K-means clustering technique in the various approaches have been applied to short-term power supply forecasting. In this paper, SARMA and intervention model are fitted to forecast the maximum power load daily, weekly, and monthly by using the empirical data from 2011 through 2013. $ARMA(2,\;1,\;2)(1,\;1,\;1)_7$ and $ARMA(0,\;1,\;1)(1,\;1,\;0)_{12}$ are fitted respectively to the daily and monthly power demand, but the weekly power demand is not fitted by AREA because of unit root series. In our fitted intervention model, the factors of long holidays, summer and winter are significant in the form of indicator function. The SARMA with MAPE (Mean Absolute Percentage Error) of 2.45% and intervention model with MAPE of 2.44% are more efficient than the present seasonal exponential smoothing with MAPE of about 4%. Although the dynamic repression model with the predictors of humidity, temperature, and seasonal dummies was applied to foretaste the daily power demand, it lead to a high MAPE of 3.5% even though it has estimation error of predictors.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1190-1199
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• 2014

As a considerable, experimental approach, an autocarriage type of $CO_2$ welding machine and a MIG(metal inert gas) welding robot in the inert gas atmosphere were utilized in order to realize Al 5083 welding to hull and relevant components of green leisure ships. This study aims at investigating the effect of welding conditions(current, voltage, welding speed, etc.) on thermal deformation that occurs as welding operation and tensile characteristics after welding, by using Al 5083, nonferrous material, applied to manufacturing of eco-environmental leisure ships. With respect to welding condition to minimize the thermal deformation, 150 A and 16 V at the wire-feed rate of 6 mm/sec were acquired in the process of welding Al 5083 through an auto carriage type of $CO_2$ welding feeder. As to tensile characteristics of Al 5083 welding through a MIG welding robot, most of tensile specimens showed the fracture behavior on HAZ(heat affected zone) located at the area joined with weld metal, except for some cases. Especially, for the case of the Al specimen with 5 mm thickness, 284.62 MPa of tensile strength and 11.41 % of elongation were obtained as an actual allowable tensile stress-strain value. Mostly, after acquiring the optimum welding condition, the relevant welding data and technical requirements might be provided for actual welding operation site and welding procedure specification (WPS).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.933-937
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• 2002

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. Pressure vessels using this composite material in comparison with conventional metal vessels can be applied in the field where lightweight and the high pressure are demanded from the defense and aerospace industry to rocket motor case due to the merits which are energy cutdown the weight reduction and decrease of explosive damage preceding to the sudden explosion which is generated by the pressure leakage condition). In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding composite pressure vessel receiving an internal pressure, the standard interpretation model is developed by using the ANSYS, general commercial software, which is verified as the accuracy and useful characteristic of the solution based on Auto LISP and ANSYS APDL. Both the preprocessor for doing exclusive analysis of filament winding composite pressure vessel and postprocessor that simplifies result of analysis have been developed to help the design engineers.