• 한국태양에너지학회 논문집
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• 제28권5호
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• pp.78-84
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• 2008

Heat pipes are considered to be promising candidates to enhance the heat transport capability of evacuated solar collectors in a wide temperature range. The working fluid must be selected properly considering various operating conditions of heat pipes for medium-high temperature range to avoid dry-out, local overheating, and frozen failure. The advantage of using binary mixture as heat pipe working fluid is that it can extend operating temperature range of the system as it can overcome operating temperature limit of a single fluid. Various operating temperature ranges were imposed in the experiments to simulate the actual operation of solar collectors using water-ethanol binary mixture. Tests were conducted for the coolant temperature range of -10$^{\circ}C$ to 120$^{\circ}C$, and mixing ratio range was from 0 to 1 based on mass fraction.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.322-323
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• 2002

Partial volume averaging effect of PET data influences on the accuracy of quantitative measurements of regional brain metabolism because spatial resolution of PET is limited. The purpose of this study was to evaluate the accuracy of partial volume correction carried out on $^{18}$ F-PET images using Hoffman brain phantom. $^{18}$ F-PET Hoffman phantom images were co-registered to MR slices of the same phantom. All the MR slices of the phantom were then segmented to be binary images. Each of these binary images was convolved in 2 dimensions with the spatial resolution of the PET. The original PET images were then divided by the smoothed binary images in slice-by-slice, voxel-by-voxel basis resulting in larger PET image volume in size. This enlarged partial volume corrected PET image volume was multiplied by original binary image volume to exclude extracortical region. The evaluation of partial volume corrected PET image volume was performed by region of interests (ROI) analysis applying ROIs, which were drawn on cortical regions of the original MR image slices, to corrected and original PET image volume. From the ROI analysis, range of regional mean values increases of partial volume corrected PET images was 4 to 14%, and average increase for all the ROIs was about 10% in this phantom study. Hoffman brain phantom study was useful for the objective evaluation of the partial volume correction method. This MR-based correction method would be applicable to patients in the. quantitative analysis of FDG-PET studies.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.3-4
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• 2006

Fast IP address lookup in routers is essential to achieve packet forwarding in wire-speed. The longest prefix matching for IP address lookup is more complex than exact matching because of its dual dimensions, length and value. By thoroughly studying the current proposals for IP address lookup, we find out that the binary search could be a low-cost solution while providing high performance. Most of the existing binary search algorithms based on trie have simple data structures which can be easily implemented, but they have some problems because of empty internal nodes. The proposed algorithm is based on trie structure, but empty internal nodes are replaced by priority prefixes. The best-matching-prefix search in the proposed algorithm is more efficiently performed since search can be finished earlier when input is matched with a priority prefix. The performance evaluation results show that the constructed priority-trie has very good performance in the lookup speed and the scalability.

• 천문학회보
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• 제43권2호
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• pp.60-60
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• 2018

It has been known that XZ CMi is a near-contact binary composed of a hotter and more massive main-sequence primary star close to its Roche-lobe and a Roche-lobe filling giant/subgiant secondary star. There still exist, however, many discordant matters among the previous investigators: diverse mass ratios and temperatures ranging from 0.38 to 0.83 and from 7,000 K to 8,876 K, respectively. In order to make a contribution to the two confusions we conducted spectroscopic and photometric observations. A total of 34 high-resolution spectra were obtained during 4 nights from 2010 and 2018 with the Bohyunsan Optical Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). In parallel, BVRI multi-band photometric observations were carried out 5 nights in 2010 at Sobaeksan Optical Astronomy Observatory (SOAO). In this presentation, we present physical parameters of XZ CMi through the simultaneous analyses of new double-lined radial velocity curves and new light curves. We will also briefly discuss the evolutionary status of the system.

• 천문학회보
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• 제39권2호
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• pp.95-95
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• 2014

The mass measurement of neutron stars or black holes is of fundamental importance in our understanding of the evolution of massive stars and core-collapse supernova explosions as well as some exotic physics of the extreme conditions. Despite the importance, however, it's very difficult to measure mass of these objects directly. One way to do this, if they are in binary systems, to measure their binary motions (i.e., Doppler shifts) which can give us direct information on their mass. Recently many new highly-obscured massive X-ray binaries have been discovered by new hard X-ray satellites such as INTEGRAL and NuSTAR. The new highly-obscured massive X-ray binaries are faint in the optical, but bright in the infrared with many emission lines. Based on the near-infrared spectroscopy, one can first understand the nature of stellar companions to the compact objects, determining its spectral types and luminosity classes as well as mass losses and conditions of (potential) circumstellar material. Next, spectroscopic monitoring of these objects can be used to estimate the mass of compact objects via measuring the Doppler shifts of the lines. For the former, broad-band spectroscopy is essential; for the latter, high-resolution spectroscopy is critical. Therefore, IGRINS appears to be an ideal instrument to study them. An IGRINS survey of these new highly-obscured massive X-ray binaries can give us a rare opportunity to carry out population analyses for understanding the evolution of massive binary systems and formation of compact objects and their mass ranges. In this talk, we will present a sample near-infrared high resolution spectra of HMXB, IGR J19140+0951 and discuss about its spectral feature. These spectra are obtained on 13th July, 2014 from IGRINS commissioning run at McDonald 2.7m telescope. And at final, we will introduce the upgrade plan of IGRINS Operation Software (IGOS), to gather the input from IGRINS observer.

• 전자공학회논문지B
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• 제29B권11호
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• pp.130-137
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• 1992

This paper presents the word recognition method using a neural-fuzzy pattern matching, in order to make a proper speech pattern for a spectrum sequence and to improve a recognition rate. In this method, a frequency variation is reduced by generating binary spectrum patterns through associative memory using a neural network, and a time variation is decreased by measuring the simillarity using a fuzzy pattern matching. For this method using binary spectrum patterns and logic algebraic operations to measure the simillarity, memory capacity and computation requirements are far less than those of DTW using a conventional distortion measure. To show the validity of the recognition performance for this method, word recognition experiments are carried out using 28 DDD city names and compared with DTW and a fuzzy pattern matching. The results show that our presented method is more excellent in the recognition performance than the other methods.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.276-277
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• 2014

Recently, carbon dioxide emissions have increased in succession according to the development of industry. also, cement of construction materials is being increased carbon dioxide during the manufacturing process. it is predicted that amount of carbon dioxide will be produced about 10 % in the world. as a way of solve this problem, it is used to reduce the amount of cement and to replace cement using industrial by-products such as blast furnace slag, fly ash, and red-mud. but, these are not advanced in our country. Thus, the purpose of this study is to analyze the strength property of binary blended geopolymer concrete. So, this study carries out the basic performance test of concrete such as, slump, air content and compressive strength.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.931-938
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• 2016

Application of vector control scheme for consumer products is enlarging to improve control performance. For the field-oriented control, accurate position detection is essential and generally requires expensive sensors. On the other hand, cost-reduction is important in home appliances, so that binary-type Hall-effect sensors are commonly used rather than using an expensive sensor such as an encoder. The control performance is directly influenced by the accuracy of the position information, and there exist non-uniformities related to Hall sensors in electrical and mechanical aspects, which result in distorted position information. Therefore, to get high-precision position information from low-resolution Hall sensors, this paper proposes a new position estimator consisting of a Kalman filter and feedforward compensation scheme, which generates a linearly changing position signal. The efficacy of the proposed scheme is verified by simulation and experimental results carried out with a 48-pole permanent magnet motor.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.468-488
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• 2016

The paper proposes a novel framework for 3D face verification using dimensionality reduction based on highly distinctive local features in the presence of illumination and expression variations. The histograms of efficient local descriptors are used to represent distinctively the facial images. For this purpose, different local descriptors are evaluated, Local Binary Patterns (LBP), Three-Patch Local Binary Patterns (TPLBP), Four-Patch Local Binary Patterns (FPLBP), Binarized Statistical Image Features (BSIF) and Local Phase Quantization (LPQ). Furthermore, experiments on the combinations of the four local descriptors at feature level using simply histograms concatenation are provided. The performance of the proposed approach is evaluated with different dimensionality reduction algorithms: Principal Component Analysis (PCA), Orthogonal Locality Preserving Projection (OLPP) and the combined PCA+EFM (Enhanced Fisher linear discriminate Model). Finally, multi-class Support Vector Machine (SVM) is used as a classifier to carry out the verification between imposters and customers. The proposed method has been tested on CASIA-3D face database and the experimental results show that our method achieves a high verification performance.

• 한국통신학회논문지
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• 제37권5C호
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• pp.437-443
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• 2012

본 논문에서는 binary offset carrier (BOC) 신호 획득을 위한 새로운 BOC 상관함수를 제안한다. 구체적으로는 BOC 자기상관함수의 주변 첨두가 불규칙적인 모양을 한 부분상관함수의 합으로 인해 나타난다는 사실을 확인하고, 부분상관함수를 새롭게 조합함으로써 주변 첨두가 없는 새로운 상관함수를 생성한다. 제안한 방법은 어떠한 종류의 BOC 신호에 대해서도 주변 첨두가 없는 상관함수를 생성할 수 있으며, 모의실험을 통해 제안한 생성함수를 이용한 경우 기존의 상관함수들을 이용한 경우에 비해 더 좋은 신호 획득 성능을 제공한다는 것을 보인다.