• 한국멀티미디어학회논문지
• /
• 제6권4호
• /
• pp.676-684
• /
• 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.

• 한국미생물·생명공학회지
• /
• 제23권5호
• /
• pp.609-616
• /
• 1995

Effects of lactate concentration, temperature, counter ions, pH as well as voltage (current) in batch electrodialysis (ED) experiments with a 3-compartment unit were investigated. The applied voltage was found to be the most critical factor as expected. The electrodialysis rate increased with the lactate concentration of the source solution. The amount of lactate transferred was limited by the lactate concentration difference between cathode and permeate compartments. The electrodialysis rate did not heavily depend on temperature change. The electrodialysis rate of NH$_{4}$-lactate was faster than that of Na-lactate and both lactates showed the highest electrodialysis rate at a pH of 4.0. A little amount of non-ionic glucose diffused through the anionic membrane to the permeate compartment. To test the effectiveness of the in situ recovery of lactic acid from fermentation broth by ED, three cases of batch culture were carried out; pH control only, ED only, and pH control and ED. The case with both pH control and ED was more efficient than that with pH control only in the aspects of productivity and product yield.

• 유기물자원화
• /
• 제3권2호
• /
• pp.91-96
• /
• 1995

서울시민을 대상으로 퇴비화 및 퇴비에 대한 일반시민의 의식조사를 실시하였다. 대부분의 시민들이 음식물쓰레기의 처리문제를 심각한것으로 인식하고 있었으며 응답자의 91.9%가 음식물쓰레기로 퇴비를 만들수 있다는 사실을 알고 있었다. 또한 화학비료보다 음식물쓰레기로 만든 퇴비를 선호하고 있었으며 가축분뇨로 만든 퇴비보다 음식물쓰레기로 만든 퇴비의 품질을 더 좋게 생각하고 있었다. 그리고 화학비료를 주고 재배한 채소보다 퇴비를 주고 재배한 채소를 좋게 생각하고 있었으며 10~20%정도의 비싼가격을 감수할 의사가 있었다. 또한 대다수의 사람들이 퇴비화를 위한 분리배출에 대해 협조할 의사를가지고 있었으며 음식물쓰레기는 소각이나 매립보다 퇴비화로 처리해야 한다고 생각하고 있었다.

• 한국환경보건학회지
• /
• 제23권3호
• /
• pp.1-6
• /
• 1997

This research was conducted in the laboratory to investigate an alternative of Copper(Cu) removal from an heavymetal wastewater using the electrochemical precipitation(ECP) process. The ECP unit consisted of an electrolytic cell made of Titanium plate and Steel plate representing anode and cathode. The DC power source applied to the ECP unit had electrical potential(E) of 50$\pm$ 1V, respectively. The synthetic wastewater used in the experiments contained Cu in the 10 mg/l concentration and the electrode separation were 2, 3, 4 cm and the initial pH were 3, 6, 9, 12, and electrolytic concentration were 0.005, 0.0125, 0.025, 0.0375 mole, and the real heavymetal wastewater used in the experiments. From the experiment for removal efficiency according to pH variation, the low pH area doesn't give the coagulation effect by Ti(OH)$_4$ because process interfere with the coagulation and oxidation reaction, therefore the optimum pH was 4-7. The removal rate was 97.75% after the lapse of 30 minutes when copper concentration and electrolytic concentration were respectively 10 mg/l and 0.025 mole. The removal rate was 96.41% after the lapse of 30minutes when the real heavymetal wastewater used. The optimum consumption of power showed 27KWh/m$^3$ when copper concentration, electrolyte concentration and cell potential were respectively 10 mg/l, 0.025 mole and 50$\pm$ 1 Volt.

• 한국지능시스템학회논문지
• /
• 제10권5호
• /
• pp.417-422
• /
• 2000

본 논문에서는 적응 뉴로-퍼지 모델링을 위해 최근에 BBS(blind source separation)분야에서 발전된 독립 성분 분석기법(ICA)을 전처리로 이용하여 효과적인 퍼지 규칙을 생성하는 방법을 제안한다. 기존의 뉴로-퍼지 모델링은 입력 데이터 성분간의 상관관계를 고려하지 않고 입력공간을 분할하기 때문에 효과적으로 분할하지 못하는 단점이 있다. 이로 인해 과도한 규칙 수와 큰 오차를 가지고 있었다. 이에, 본 연구에서는 독립 성분 분석기법을 이용하여 입력 데이터 성분간의 상관관계를 제거함으로서 적은 규칙 수를 갖으면서도 효율적인 퍼지 규칙을 얻을 수 있도록 하였다. 시뮬레이션 예로서 Box-Jenkins의 가스로 데이터의 모델링에 적용하여 유용성과 제안된 방법이 이전의 연구보다 좋은 결과를 보임을 알 수 있었다.

• 제어로봇시스템학회논문지
• /
• 제13권9호
• /
• pp.838-842
• /
• 2007

A brain-computer interface(BCI) system is a communication channel which transforms a subject's thought process into command signals to control various devices. These systems use electroencephalographic signals or the neuronal activity of many single neurons. The presented study deals with an efficient analysis method of neuronal signals from a BCI System using an independent component analysis(ICA) algorithm. The BCI system was implemented to generate event signals coding movement information of the subject. To apply the ICA algorithm, we obtained the perievent histograms of neuronal signals recorded from prefrontal cortex(PFC) region during target-to-goal(TG) task trials in the BCI system. The neuronal signals were then smoothed over 5ms intervals by low-pass filtering. The matrix of smoothed signals was then rearranged such that each signal was represented as a column and each bin as a row. Each column was also normalized to have a unit variance. As a result, we verified that different patterns of the neuronal signals are dependent on the target position and predefined event signals.

• Nuclear Engineering and Technology
• /
• 제34권5호
• /
• pp.494-501
• /
• 2002

Radioactive Corrosion Products (CRUD) which are generated by the neutron activation of general corrosion products at the nuclear power plant are the major source of occupational radiation exposure. Most of the CRUD has a characteristic of showing strong ferrimagnetisms. Along with the new development and production of permanent magnet (rare earth magnet) which generates much stronger magnetic field than the conventional magnet, new type of magnetic filter that can separate CRUD efficiently and eventually reduce radiation exposure of personnel at nuclear power plant is suggested. This separator consists of inner and outer magnet assemblies, coolant channel and container surrounding the outer magnet assembly. The rotational motion of the inner and outer permanent magnet assemblies surrounding the coolant channel by driving motor system produces moving alternating magnetic fields in the coolant channel. The CRUD can be separated from the coolant by the moving alternating magnetic field. This study describes the results of preliminary experiment performed with the different flow rates of coolant and rotation velocities of magnet assemblies. This new magnetic filter shows better performance results of filtering the magnetite at coolant (water). How rates, rotating velocities of magnet assemblies and particle sizes turn out to be very important design parameters.

• 한국유기농업학회지
• /
• 제21권1호
• /
• pp.1-18
• /
• 2013

Animal and crop production systems were integrated on a single farm. This integrated farming system recycled nutrients on the farm. The separation of animal and crop production with the introduction of cheap commercial fertilizers, farms were not used land-applied manure. The on-line manure matching is one of the emerging business in the achievement of recycling and resource recovery. The manure matching actively promotes the reuse and recycling of by-products and manure. This study constructs to manure matching information system to solve the exchange problems between herders and croppers. Manure matching web sites designed. This paper introduces a web-based animal manure matching system. A manure matching service, part of the manure transport, links farmers who produce excess manure with farmers who can use the manure. Farmers registered with the service have requested manure. The manure matching service supports the transport project by linking farmers with excess manure with those farmers who can utilize the manure safely as a nutrient source. The goal of the service is to protect water quality by fostering efficient land application. Benefits to those who use the manure network include reduced disposal costs, lower purchase costs and recycling of manure. The manure matching is based on the principle that 'one persons waste is another person's fertilizer.' It provides a free online matchmaking service for environmentally safe manure recycling management system.

• International journal of advanced smart convergence
• /
• 제9권2호
• /
• pp.20-27
• /
• 2020

Sound event detection in real-world environments suffers from the interference of non-stationary and time-varying noise. This paper presents an adaptive noise reduction method for sound event detection based on non-negative matrix factorization (NMF). In this paper, we proposed a deep learning model that integrates Convolution Neural Network (CNN) with Non-Negative Matrix Factorization (NMF). To improve the separation quality of the NMF, it includes noise update technique that learns and adapts the characteristics of the current noise in real time. The noise update technique analyzes the sparsity and activity of the noise bias at the present time and decides the update training based on the noise candidate group obtained every frame in the previous noise reduction stage. Noise bias ranks selected as candidates for update training are updated in real time with discrimination NMF training. This NMF was applied to CNN and Hidden Markov Model(HMM) to achieve improvement for performance of sound event detection. Since CNN has a more obvious performance improvement effect, it can be widely used in sound source based CNN algorithm.

• 한국의학물리학회지:의학물리
• /
• 제10권1호
• /
• pp.9-15
• /
• 1999

혈액에서의 산소 포화도는 Hb와 HbO$_2$의 광학 스펙트라에서 흡수계수의 차이에 의해서 측정할 수 있다. 본 연구는 하지 조직에서 발생하는 말초혈관계 질환진단을 위하여 파장이 660nm 와 940nm의 LED를 이용하여 산소포화도를 측정하는 장치를 개발하였다. 산소측정장치는 광 탐촉자와 광 신호처리부, LED 구동회로, 컴퓨터와 인터페이스로 구성하고, 데이터의 수집과 분석을 위한 프로그램 을 개발하였다. 구현된 산소측정장치에 대한 임상적인 평가를 위하여 하지조직에서 운동 부하에 따른 실험을 하여 생체조직내 생리적변화에 따른 산소량의 변화를 측정하고, 기기의 성능을 평가하였다. 실험결과 생체조직내의 산소포화도는 광원과 검출기의 간격에 따라 측정이 가능함을 보여 주었다.