• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.8
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• pp.1152-1163
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• 1998

In the present work, the image processing technique for measurement of drop sizes has been improved. Firstly, the local processing concept was adopted in addition to the global processing technique to take account of non-uniformity of the illumination intensity ; thereby, basically, the measurement error can be reduced. Also, the unfocussed image of drops can be eliminated more precisely since the elimination process is based on the local normalized contrast. Secondly the algorithms to process the partially detected or overlapped drop images and the non-spherical drop images were developed. Finally, the improved algorithm was tested by using an artificially prepared image-frame, where the partial or overlapped particles and the non-spherical particles are mixed with the normal spherical ones (with their true size-distributions known a priori). The results showed that both the recognition rate of the number of particles and the measurement accuracy were improved prominently.

• Journal of the Korean School Mathematics Society
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• v.6 no.1
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• pp.19-26
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• 2003

The purpose of this study is twofold: (i) to argue the importance of problem solving strategy in education and (m to propose an efficient way to use the problem-solving strategy, which is based on the survey to find out how well elementary school teachers recognize the importance of the strategy. Forty elementary school teachers participated in the survey. The result of the survey shows that they do not use various strategies when they solve problems. It also shows that the rate of wrong answers the teachers get when solving problems is pretty high because they adopt a wrong strategy. It is prerequisite that teachers recognize the importance of the strategy when solving problems and put into practice various strategies in order to help their students improve their problem-solving abilities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.114-130
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• 2020

Balinese calendar is defined as a unique calendar system for combining solar-based and lunar-based system and assuming local system. It is considered as guidance of Balinese societies' activities management, starting from meeting arrangement, wedding ceremony, to religious ceremonies. Practically, it has developed in the form of printed Balinese calendar and electronic Balinese calendar, either web or mobile application. The core of the function is to find out the day with its various characteristics in the Balinese Calendar. In general, society usually asks the religious leader to find out the day in detail. The technology of NLP combined with models of pattern discoveries supports the arrangement of the interaction model in searching the good day in Balinese Calendar to equip the conventional searching system in the previous applications. This study will design a dialog model with AIML method in multi-parameter basis; therefore, the users will be dynamically able to use the searching content in various ways by chatting in similar with consulting to a religious leader. This model will be applied in a chatbot basis service in telegram machine. The addition of the context recognition section into 4 paterns has been successfully improve the ability of AIML to recognize input patterns with many criteria. Based on the testing with 50 random input patterns obtained a success rate of 92.5%.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.4
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• pp.377-389
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• 2014

In recent years, Smart Water Grid (SWG) concept has globally emerged over the last decade and also gained significant recognition in South Korea. Especially, there has been growing interest in water demand forecast and this has led to various studies regarding energy saving and improvement of water supply reliability. In this regard, this study aims to develop a nonlinear ensemble model for hourly water demand forecasting which allow us to estimate uncertainties across different model classes. The concepts was demonstrated through application to observed from water plant (A) in the South Korea. Various statistics (e.g. the efficiency coefficient, the correlation coefficient, the root mean square error, and a maximum error rate) were evaluated to investigate model efficiency. The ensemble based model with an cross-validate prediction procedure showed better predictability for water demand forecasting at different temporal resolutions. In particular, the performance of the ensemble model on hourly water demand data showed promising results against other individual prediction schemes.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1103-1109
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• 2011

This research quantitatively confirmed an acoustical anisotropy that exists in a pure titanium plate from the signal of ultrasonic flow detection and suggested a new way to evaluate the acoustical anisotropy by inputting acquired characteristic of ultrasound signal into the neutral network. Using the fact with the suggested method that the characteristic of ultrasound signal is shown differently depending on the pure titanium plate's rolling direction, the neural network was constructed by extracting the characteristic that can decide each direction of $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ with waveform analysis program. As a result of inputting the characteristic of ultrasound signal acquired from a random rolling direction into the neural network that was built like this, it showed a pattern recognition rate higher than 95% on directions of $0^{\circ}$, $45^{\circ}$, $90^{\circ}$.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.2
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• pp.249-254
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• 2014

We have studied on the possibility of railway stability system using RFID tag. UHF RFID tag was desinged, manufactured and tested. Proposed UHF tag antenna has PIFA type structure and inset feed multi matching technique was attempted for impedance matching of antenna. The impedance bandwidth (VSWR < 3) of the proposed tag antenna covers 917~923 MHz. Measured peak gain is 3.225 dBi and UHF band with an omni-directional radiation pattern. RFID reader and tag installed in motor car and track, respectively. Then, tag recognition rate according to velocity of car (under 45 km/h) represented 100 %.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.3-11
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• 2010

In this paper we propose a new algorithm to detect the irises of both eyes from a human face. Using the separability filter, the algorithm first extracts blobs(intensity valleys) as the candidates for the irises. Next, for each pair of blobs, the algorithm computes a cost using Hough transform and separability filter to measure the fit of the pair of blobs to the image. And then, the algorithm selects a pair of blobs with the smallest cost as the irises of both eyes. As the result of the experiment using 150 faces images without spectacles, the success rate of the proposed algorithm was 97.3% for the best case and 95.3% for the worst case.

• ETRI Journal
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• v.32 no.5
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• pp.729-739
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• 2010

Due to the rapid development of mobile devices equipped with cameras, instant translation of any text seen in any context is possible. Mobile devices can serve as a translation tool by recognizing the texts presented in the captured scenes. Images captured by cameras will embed more external or unwanted effects which need not to be considered in traditional optical character recognition (OCR). In this paper, we segment a text image captured by mobile devices into individual single characters to facilitate OCR kernel processing. Before proceeding with character segmentation, text detection and text line construction need to be performed in advance. A novel character segmentation method which integrates touched character filters is employed on text images captured by cameras. In addition, periphery features are extracted from the segmented images of touched characters and fed as inputs to support vector machines to calculate the confident values. In our experiment, the accuracy rate of the proposed character segmentation system is 94.90%, which demonstrates the effectiveness of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.8
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• pp.692-698
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• 2013

As the mobile marketing through the smartphone has gradually increased, the smartphone application services using the AR marker, QR codes and augmented reality have attracted much attention. Furthermore the outdoor advertising is migrated to LED signage, which brings the visible light wireless communication technologies to the trial for mobile marketing. In this paper we present the implementation of AR marker-based URL access application services through smartphone camera using visible-light wireless communication technologies. We analyze the performance of the implemented system in terms of connection time and success rate.

• Annual Conference of KIPS
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• 2017.04a
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• pp.312-314
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• 2017

생체정보를 이용한 사용자 인증은 차세대 인증 방법으로서 기존의 인증 시스템에서 급진적으로 사용되고 있는 인증 방법이다. 현재 대부분의 생체인증 시스템은 단일 생체정보를 이용하고 있는데, 단일 생체인증 시스템은 노이즈로 인한 문제, 데이터의 질에 대한 문제, 인식률의 한계 등 많은 문제점들을 가지고 있다. 이를 해결하기 위한 방법으로 다중 생체정보를 이용하는 사용자 인증 방법이 있다. 다중 생체인증 시스템은 각각의 정보에 대한 information fusion을 적용하여 새로운 정보를 생성한 뒤, 그 정보를 기반으로 사용자를 인증한다. information fusion 방법들 중에서도 Rank-level fusion 방법은 표준화 작업이 필요하고 높은 계산 복잡도를 갖는 Score-level fusion방법의 대안으로 선택되고 있다. 따라서 본 논문에서는 기존 방법보다 정확도가 높게 향상된 Rank-level fusion 방법을 제안한다. 또한, 본 논문에서 제안하는 방법은 낮은 정확도를 갖는 matcher를 사용하더라도 정확도를 향상시킬 수 있음을 실험을 통해 보이고자 한다.