• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.597-607
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• 2008

ATIS(Advanced Traffic Information System) provide valuable information as the travel time and traffic congestion, detour, traffic accident information to drivers, so it is being in the spotlight. But so far, the study on the consumer satisfaction with providing traffic information is incomplete. So, this study run a Canonical discriminant analysis and a Canonical correlation analysis by a QuantificationIItheory based on a Traffic Information Satisfaction image data through questionnaires, and found out the factors with influence on the consumer satisfaction. And this study definitely found out the correlation between consumer's recognition and traffic information satisfaction through understanding the change on the recognition about traffic information satisfaction by a QuantificationItheory. Finally, this study found out the change on the sensibility recognition of drivers by running the principal component anlysis, developed the traffic information satisfaction evaluation model considering the change on the recognition by using the structural equation model.

• Journal of The Korean Association For Science Education
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• v.27 no.3
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• pp.253-262
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• 2007

This study is an investigation regarding the understanding of the nature of science among pre-service science teachers majoring in science education. We interviewed 22 senior students in science education who finished their internship courses. Students were interviewed individually for approximately 20 minutes each. Data from semi-structured interview were audio-recorded and transcribed for the analysis. Findings indicated that participants held more complete understanding of the nature of scientific knowledge than the nature of scientific enterprise. Their understandings of the nature of scientific method was that hypothetical-deductive method is more scientific than descriptive-narrative method and there is a single stepwise scientific method to solve problems. These results showed that they have a narrow view of the nature of science. Thus, teacher education programs need to integrate the understanding of the nature of science throughout.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.126-134
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• 2017

There have been numerous studies on extracting the R-peak from electrocardiogram (ECG) signals. However, most of the detection methods are complicated to implement in a real-time portable electrocardiograph device and have the disadvantage of requiring a large amount of calculations. R-peak detection requires pre-processing and post-processing related to baseline drift and the removal of noise from the commercial power supply for ECG data. An adaptive filter technique is widely used for R-peak detection, but the R-peak value cannot be detected when the input is lower than a threshold value. Moreover, there is a problem in detecting the P-peak and T-peak values due to the derivation of an erroneous threshold value as a result of noise. We propose a robust R-peak detection algorithm with low complexity and simple computation to solve these problems. The proposed scheme removes the baseline drift in ECG signals using an adaptive filter to solve the problems involved in threshold extraction. We also propose a technique to extract the appropriate threshold value automatically using the minimum and maximum values of the filtered ECG signal. To detect the R-peak from the ECG signal, we propose a threshold neighborhood search technique. Through experiments, we confirmed the improvement of the R-peak detection accuracy of the proposed method and achieved a detection speed that is suitable for a mobile system by reducing the amount of calculation. The experimental results show that the heart rate detection accuracy and sensitivity were very high (about 100%).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.344-350
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• 2009

This paper proposes a hybrid antenna with novel beam steering scheme. The antenna have a cassegrain structure composed of two reflectors. The main reflector is designed for high gain performance using parabola curvature, and the sub-reflector is plate and can be rotated by ${\pm}3^{\circ}$. Thus proposed antenna can steer a antenna beam using the inclination of sub-reflector. A feed array composed of 20 elements is adapted as a feeder for electrical beam steering, and the antenna can be possible to steer the beam by the feed array with sub-reflector. Proposed antenna was fabricated to be operated in Ka-band(30.085$\sim$30.885 GHz) for TX and K-band(20.355$\sim$21.155 GHz), which are the operation frequencies of the Korean satellite, Mugunhwa, to provide satellite multi-media service to vehicles. By the performance test, it can be known that the antenna has minimum gain of 47 dBi for TX and 44.4 dBi for TX and can steer the beam by ${\pm}2^{\circ}$ with sub-reflector.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.119-119
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• 2010

무한 지속 가능한 지열 에너지를 활용한 공조시스템인 지열원 냉난방 시스템은 기존의 공조 시스템보다 열원이 안정적이기 때문에 높은 효율과 우수한 성능을 가지므로, 기후변화협약 대응의 주요수단으로서 기술개발과 보급이 증대되고 있다. 본 연구에서는 대수층 축열 지열원 열펌프 시스템에 대한 실증 연구를 통하여 대수층 축열 지열원 열펌프 시스템의 하절기 냉방 성능을 분석하였다. 대수층 축열 냉난방 시스템은 주입정과 양수정의 2개의 우물공이 설치되어 있으며, 겨울 난방 운전 중에 한 개의 우물공으로부터 지하수를 열펌프로 유입한 후 낮은 온도의 지하수를 타 우물공에 축열하고, 하절기에 겨울에 저온으로 축열된 우물공으로부터 지하수를 열펌프로 유입하여 온도가 증가된 지하수를 타 우물공에 주입한다. 즉, 계절별로 열펌프에서 생성된 냉수와 온수의 대수층 축열을 위하여 계절별로 주입정과 양수정이 바뀌게 된다. 본 연구의 대수층 축열 지열원 열펌프 시스템의 2009년 8월의 주요일자별 시스템 운전 중의 평균 냉방 열펌프 유닛 COP와 냉방 시스템 COP는 각각 4.7과 3.4이상의 우수한 성능을 나타냈다. 또한, 모든 일자에 대하여 외기온도가 $31.6^{\circ}C$서 $22^{\circ}C$까지 변화가 크게 나타났지만 열펌프 유닛 COP와 시스템 COP의 변화는 미소하였다. 이는 양수정으로부터의 지중 순환수가 운전기간 중에 $17.5^{\circ}C$로 일정하게 유지되었기 때문이다. 양수정과 주입정 사이에 5개의 관측공을 설치하였으며, 양수정 측에 인접한 관측공의 온도는 거의 변화가 없었으며, 단기간이지만 널리 사용되고 있는 수직밀폐형 시스템과 달리 지속적인 냉방운전 중의 양수 온도의 증가는 발생하지 않아 안정적인 성능을 나타냈다. 주입정에 인접한 모니터링 홀의 온도는 심도가 깊은 곳의 온도가 낮은 곳보다 높게 나타났다. 이는 냉방 운전 시 열펌프 유닛의 실외열교환기에서 지중 순환수가 냉매로부터 열을 취득하여 온도가 상승하면서 주입정측에 온열이 축열이 진행되었기 때문으로 분석되며, 하절기의 냉방 운전 시간이 증가할 경우 축열 효과는 더욱 증가할 것으로 예상된다. 양수정과 주입정 중간의 모니터링 홀의 온도는 2009년 8월 가동 중에 온도변화는 없었는데, 이는 양수정과 주입정 사이의 열간섭이 발생하지 않았기 때문으로 분석된다. 일자별로 운전 중의 열펌프 유닛 COP는 차이가 없었지만, 운전 및 정지 시간을 모두 포함한 시스템 소비전력과 냉방용량을 모두 합산하여 산정한 일일 평균 냉방 열펌프 유닛 COP와 냉방 시스템 COP는 일자별로 다소 차이가 발생하였는데, 이는 각 일자별로 열펌프 유닛 가동율의 차이로 인하여 열펌프 유닛 가동 전에 먼저 작동되는 지중순환펌프의 운전 소비전력의 차이와 열펌프의 단속운전 시의 열손실과 추거 소비전력의 차이 때문이다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.8-15
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• 2006

To reduce costs and address other practical concern related to architectural lighting, we have been involved in various aspects of advanced daylighting design and control. If we look toward future building trends, we see that the advanced has already successfully deployed such complex lighting control systems. This paper takes a broad view of what advanced manufacturers have done to develop energy efficient lighting control technologies such as sensors, lumen maintenance, time of day scheduling, peak demand reduction and so forth. First of all strategies, daylighting controls would also need to be commissioned to respond to the specific daylighting signature of the zone. To translate the daylight in term of the amount of energy savings, an electric lighting system is designed and automatic on-off control system integrated with the contribution of daylighting has been applied to the operating of the artificial lighting. The lighting analysis program, Lumen-Micro predicts the optimal layout of conventional fluorescent and incandescent lighting fixtures to meet the designed lighting level and calculates unit power density, which translates the demanded amount of lighting energy.

• Analytical Science and Technology
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• v.27 no.2
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• pp.79-91
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• 2014

Solubility data of carbon dioxide ($CO_2$) in 1-butyl-3-methylpiperidinium bis(trifluoromethylsulfonyl)imide ($[bmpip][Tf_2N]$) ionic liquid are presented at pressures up to about 30 MPa and at temperatures between 303 K and 343 K. As far as we know, the data on the $CO_2$ solubility in the $[bmpip][Tf_2N]$ ionic liquid have never been reported in the literature by other investigators. The solubilities of $CO_2$ were determined by measuring the bubble point or cloud point pressures of the $CO_2+[bmpip][Tf_2N]$ mixtures with various compositions using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. To observe the effect of the cation composing the ionic liquid on the $CO_2$ solubility, the $CO_2$ solubilities in $[bmpip][Tf_2N]$ used in this study were compared with those in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide ($[bmim]Tf_2N]$). As the equilibrium pressure increased, the $CO_2$ solubility in $[bmpip][Tf_2N]$ increased sharply. On the other hand, the $CO_2$ solubility decreased with increasing temperature. The mole fraction-based $CO_2$ solubilities were almost the same for both $[bmpip][Tf_2N]$ and $[bmim][Tf_2N]$, regardless of temperature and pressure. The phase equilibrium data for the $CO_2+[bmpip][Tf_2N]$ systems have been correlated using the Peng-Robinson equation of state.

• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.369-386
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• 2005

Although Intelligent Tutoring System(ITS) offers individualized learning environment that overcome limited function of existent CAI, and consider many learners' variable, there is little development to be using at the sites of schools because of inefficiency of investment and absence of pedagogical content knowledge representation techniques. To solve these problem, we should study a method, which represents knowledge for ITS, and which reuses knowledge base. On the pedagogical content knowledge, the knowledge in education differs from knowledge in a general sense. In this paper, we shall primarily address the multi-complex structure of knowledge and explanation of learning vein using multi-complex structure. Multi-Complex, which is organized into nodes, clusters and uses by knowledge base. In addition, it grows a adaptive knowledge base by self-learning. Therefore, in this paper, we propose the 'Extended Neural Logic Network(X-Neuronet)', which is based on Neural Logic Network with logical inference and topological inflexibility in cognition structure, and includes pedagogical content knowledge and object-oriented conception, verify validity. X-Neuronet defines that a knowledge is directive combination with inertia and weights, and offers basic conceptions for expression, logic operator for operation and processing, node value and connection weight, propagation rule, learning algorithm.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.29-38
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• 2012

The noise generated in the process of obtaining the medical image acts as the element obstructing the image interpretation and diagnosis. To restore the true image from the image polluted from the noise, the total variation optimization algorithm was proposed by the R.O. F (L.Rudin, S Osher, E. Fatemi). This method removes the noise by fitting the balance of the regularity and fidelity. However, the blurring phenomenon of the border area generated in the process of performing the iterative operation cannot be avoided. In this paper, we propose the adaptive total variation method by mapping the control parameter to the proposed transfer function for minimizing boundary error. The proposed transfer function is determined by the noise variance and the local property of the image. The proposed method was applied to 464 tooth images. To evaluate proposed method performance, PSNR which is a indicator of signal and noise's signal power ratio was used. The experimental results show that the proposed method has better performance than other methods.

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.41-49
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• 2010

Furan-containing epoxide monomers (8, 9) were designed and synthesized as carbon-neutral, environment-friendly adhesion material. Bicyclic skeleton were constructed using the Diels-Alder reaction of furan and methyl acrylate, both readily accessible starting material from a biomass via bio-refinery process. After reduction of ester functionality, resulting hydroxyl moieties were coupled to epichlorohydrin to provide the epoxy-functionalized furanic monomers (8, 9). The structure of new furanic monomers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy. As UV-curable monomers, basic properties such as UV curing time and the extent of UV curing were evaluated by photo DSC. Photo-curing shrinkages were measured by linear variable differential transformer transducer (LVDT) and the effect of molecular structure on shrinkage was considered. In addition, new synthetic compounds showed the shear strength over 3 MPa when they were photo-cured between polycarbonate plates, which indicates these compounds are feasible to use as photo-curable adhesive materials.