• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.61-67
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• 2002

The joint warfighting environment, arranged by the net work-centrics, consists, with the situational awareness, the battlespace deconfliction, the joint force ID/location/allocation, and the ordnance on targets, considered by the concepts evolving In meet the future scenarios and threats. And then, the next generation warships have the operational requirements, such as the major offensive capability, the low operating cost, the ability to operate in net. centric forces, the revolutionary stealth, the in-stride mine avoidance, and the revolutionary manning. Therefore, the proposal discussed at this paper will be accepted in order to resolve only the portion of the afore-mentioned problems.

• Journal of the Korean Data and Information Science Society
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• v.20 no.3
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• pp.485-492
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• 2009

In this paper, we studied process capability analysis for brake-pad manufacturing system and considered Weibull, normal and logistic distributions for density estimation of wear life of brake pads for a passenger car with a real data. These three distributions are seem to work well. Estimated percentiles of brake pads can be used to evaluate the design criteria and customers' need for brake pads.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1330-1335
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• 2012

This paper proposes an automatic measurement sampling method for the semiconductor manufacturing process. The method recommends sampling rates using information of process capability indexes and production scheduling plan within the restricted metrology capacity. In addition, it automatically controls the measurement WIP (Work In Process) using measurement priority values to minimize the measurement risks and optimize the measurement capacity. The proposed sampling method minimizes measurement controls in the semiconductor manufacturing process and improves the fabrication productivity via reducing measurement TAT (Turn Around Time), while guaranteeing the level of process quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2B
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• pp.11-20
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• 2005

Strict priority scheduling scheme is a good candidate for the implementation of service differentiation in an Internet because of simplicity in implementation and the capability to guarantee the delay requirement of the highest class of traffic. However, it is also blown that strict priority starves the lower-class traffic at the cost of prioritizing the higher-class traffic. The purpose of this work is to propose an analytic method which can estimate the average delay performance of Diffserv service architecture and shows that strict priority scheme does not sacrifice the lower class traffic over a diverse condition of the load. From the numerical experiments for three-class Diffserv network we validate our argument that strict priority scheme may be applied to a service differentiation scheme for the future Internet.

• Information and Communications Magazine
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• v.30 no.10
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• pp.79-85
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• 2013

By interacting with external wireless sensors, smartphones can gather high-fidelity data on the surrounding environment to develop various environment-aware, personalized applications. In this work we introduce the sensor virtualization module (SVM), which virtualizes external sensors so that smartphone applications can easily utilize a large number of external sensing resources. Implemented on the Android platform, our SVM simplifies the management of external sensors by abstracting them as virtual sensors to provide the capability of resolving conflicting data requests from multiple applications and also allowing sensor data fusion for data from different sensors to create new customized sensors elements. We envision our SVM to open the possibilities of designing novel personalized smartphone applications.

• Journal of Power Electronics
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• v.9 no.1
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• pp.36-42
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• 2009

This paper presents a review of an improved high power-high frequency III-V wide bandgap (WBG) semiconductor device, Gallium Nitride (GaN). The device offers better efficiency and thermal management with higher switching frequency. By having higher blocking voltage, GaN can be used for high voltage applications. In addition, the weight and size of passive components on the printed circuit board can be reduced substantially when operating at high frequency. With proper management of thermal and gate drive design, the GaN power converter is expected to generate higher power density with lower stress compared to its counterparts, Silicon (Si) devices. The main contribution of this work is to provide additional information to young researchers in exploring new approaches based on the device's capability and characteristics in applications using the GaN power converter design.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.629-638
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• 2020

In this paper, an unmanned automation system for harvesting chili peppers through image recognition in the color space is proposed. We developed a cutting-edge technology in terms of convergence between information and communication technology (ICT) and agriculture. Agriculture requires a lot of manpower and entails hard work by the laborers. In this study, we developed an autonomous application that can obtain the head coordinates of a chili pepper using image recognition based on the OpenCV library. As an alternative solution to labor shortages in rural areas, a robot-based chili pepper harvester is proposed as a convergence technology between ICT and agriculture requiring hard labor. Although agriculture is currently a very important industry for human workers, in the future, we expect robots to have the capability of harvesting chili peppers autonomously.

• Journal of Power Electronics
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• v.8 no.2
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• pp.141-147
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• 2008

This paper deals with a new and improved control technique for shunt active filters (AF) used for compensating unwanted harmonic currents injected in the mains due to nonlinear varying loads. This work is motivated by the need to find a permanent solution to the rigorous hit and trial method for evaluating system parameters in an indirect control of AF. A fuzzy pre-compensated PI (Proportional-Integral) controller is used to fuzzify the reference DC voltage of AF to the controller input so that the overshoots and undershoots in its DC link voltage are minimized and the settling time is improved. A three-phase diode rectifier with R-L (Resistive-Inductive) load is used as a non-linear load to study the effectiveness of the proposed controller of the AF. Robustness to filter parameter variations, insensitivity to controller parameter variations, and transient response has been taken as performance evaluation parameters. The results are shown through simulations in Matlab using power system block sets to demonstrate the capability of the proposed controller of the AF.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.332-334
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• 1994

This paper proposes a robust active noise control (ANC) system. The system constructs filter with a standard model. An adaptive litter, connected to the system in parallel, compensates the modeling error. When the adaptive filter does not work, the proposed system is robust while the conventional system loses the noise control capability. But proposed ANC system shows that the performance is comparable with that of the conventional ANC system under normal conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.689-693
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• 2005

Inkjet printing is a non-contact and direct writing associated with a computer. In the industrial field, there have been many efforts to utilize the inkjet printing as a new way of manufacturing, especially for electronic devices. For the application of inkjet printing to electronic field, one of the key factors is exact realization of designed images into printed patterns. In this work, micro patterning for conducting line has been studied using the piezoelectric print head and silver nano ink. Dimensions of printed images have been predicted in terms of print resolution and diameter of a single dot. The predicted and the measured values showed consistent results. Using the results, the design capability for industrial inkjet printing could be achieved.