• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.6
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• pp.623-632
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• 2015

This study proposes a control strategy of the common rail pressure with a fuel injection limitation algorithm to reduce particulate matter (PM) emissions under transient states. The proposed control strategy consists of two parts: injection quantity limitation and rail pressure adaptation. The injection limitation algorithm determines the maximum allowable fuel injection quantity to avoid rich combustion under transient states. The fuel injection quantity is limited by predicting the burned gas rate after combustion; however, the reduced injection quantity leads to deterioration of engine torque. The common rail pressure adaptation strategy is designed to compensate for the reduced engine torque. An increase of the rail pressure under transient states contributes to enhancement of the engine torque as well as reduction of PM emissions by promoting atomization of the injected fuel. The proposed control strategy is validated through engine experiments. The rail pressure adaptation reduced the PM emission by 5-10% and enhanced the engine torque up to 2.5%.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.214-218
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• 1988

This paper suggests mathemathical engine model which can simulate generalized gasoline engine. Suggested engine model contains air/fuel inlet element, intake manifold, combustion, engine dynamics. In order to analyze a gasoline engine, physical characteristics of engine and steady state engine data should be controlled. In adaptation for abrupt change of circumstance or drive conditions, this model can analyze important physical phenomena in the intake manifold by computer simulation. This model can also evaluate statuses of drive under various working conditions precisely. Therfore, this model suggests basic datum to evaluate the engine system which are needed in designing and development of engine controller.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.4
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• pp.346-351
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• 2011

Medium and high speed marine diesel engines with reduction gear have been widely used as prime mover in small car ferries and fishing vessels. The elastic coupling should be installed and complemented the propulsion shafting system to isolate the vibratory torque between engine and reduction gear. In this paper, the dynamic characteristics of elastic coupling with rubber type circular segments is confirmed by theoretical analysis using the FEM and the hydraulic excitation test at shop. Further adaptation was investigated with the torsional vibration test at diesel engine factory shop.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.313-322
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• 2005

In order to access digital items in a server via ubiquitous devices, the digital items should be adapted according to the system environment, device characteristics and user preferences. In ubiquitous environment, those device-dependent adaptation requirements are not statically determined and not predictable. Therefore an application specific adaptation mechanism can not be applied to a general digital item adaptation engine. In this paper, we propose an application independent digital item adaptation architecture which has a set of minimal transcoders, transcoding path generator for a required adaptation requirement, and adaptation scheduler. And a CFG based method of finding a sequence of multiple unit transcoders called a transcoding path Is described in detail followed by experimental results.

• The KIPS Transactions:PartA
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• v.14A no.6
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• pp.363-370
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• 2007

The ubiquitous computing environment could provide better service to users by adapting to changing contexts. In this paper, we developed a context adaptation system, which enables an ubiquitous program to adapt to different contexts, following its adaptation rules. Using this system, programmers can develop ubiquitous programs suitable for changing contexts, by describing the context adaptation policy. The context adaptation engine of this system fits the ubiquitous program to the current context based on the context adaptation rules. This system was implemented using JCAF, context-aware programing framework based on java. A simulator is also provided to simulate ubiquitous programs by changing contexts.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.214-219
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• 2003

This paper includes real-time tractive force estimation method using standard vehicle sensors such as wheel speed, brake pressure, throttle position, engine speed, and transmission carrier speed sensor. Engine map, torque converter lookup table, shaft torque observer, and brake gain adaptation method are used to estimate the tractive force. To verify this estimator, measurement which uses strain-based brake torque sensor and estimation results are presented. All results was performed using a real vehicle in a real-time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.90-95
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• 2008

Medium and high speed marine diesel engines have been widely used as prime mover in small car ferries and fishing vessels with reduction gear. These propulsion shafting system should be installed and matched the elastic coupling between engine and reduction gear to isolate the vibratory torque. In this paper, the elastic dynamic characteristics of coupling with rubber type circular segments is confirmed by the theoretical analysis using the FEM and the hydraulic exciting test at shop. And its adaptation is investigated in the torsional vibration test in factory shop.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.6
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• pp.379-385
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• 2006

To improve reusability and adaptation of variable components, rule-based component development has been used. Rule engines usually need additional script languages for rule expression and have difficulty in expressing complex business rules. In this paper, we propose a compiler-based rule engine for rich rule expression and improving performance. This rule engine uses Java programming language to express conditions and action parts of rules and that it can easily express complex business rules. It creates and executes condition and action objects at run time. In view of Performance, the rule engine is better than a script based rule engine. According to our experiments, our compiler-based nile engine shows 2.5 times better performance that script-based JSR 94 rule engine.

• Journal of Korea Multimedia Society
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• v.6 no.4
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• pp.676-684
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• 2003

eLearning can be defined as an approach to teaching and teaming that utilises Internet technologies to communicate and collaborate in an educational context. This includes technology that supplements traditional classroom training with web-based components and learning environments where the educational process is experienced online. The use of hypertext as an educational tool has a very rich history. The advent of the internet and one of its major application, the world wide web (WWW), has given a tremendous boost to the theory and practice of hypermedia systems for educational purposes. However, the web suffers from an inability to satisfy the heterogeneous needs of a large number of users. For example, web-based courses present the same static teaming material to students with widely differing knowledge of the subject. Adaptive hypermedia techniques can be used to improve the adaptability of eLearning. In this paper we report an approach to the design a unified implementation framework suitable for web-based eLearning that accommodates the three main dimensions of hypermedia adaptation: content, navigation, and presentation. The framework externalises the adaptation strategies using XML notation. The separation of the adaptation strategies from the source code of the eLearning software enables a system using the framework to quickly implement a variety of adaptation strategies. This work is a part of our more general ongoing work on the design of a framework for adaptive content delivery. parts of the framework discussed in this paper have been imulemented in a commercial eLearning engine.

• Journal of the Korea Convergence Society
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• v.4 no.3
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• pp.43-50
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• 2013

This paper presents a model predictive control (MPC) based on a neural network (NN) model for air/fuel ration (AFR) control of automotive engines. The novelty of the paper is that the severe nonlinearity of the engine dynamics are modelled by a NN to a high precision, and adaptation of the NN model can cope with system uncertainty and time varying effects. A single dimensional optimization algorithm is used in the paper to speed up the optimization so that it can be implemented to the engine fast dynamics. Simulations on a widely used mean value engine model (MVEM) demonstrate effectiveness of the developed method.