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Cycle Detection of Discrete Logarithm using an Array (배열을 이용한 이산대수의 사이클 검출)

  • Sang-Un Lee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.5
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    • pp.15-20
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    • 2023
  • Until now, Pollard's Rho algorithm has been known as the most efficient way for discrete algebraic problems to decrypt symmetric keys. However, the algorithm is being studied on how to further reduce the complexity of O(${\sqrt{p}}$) performance, along with the disadvantage of having to store the giant stride m=⌈${\sqrt{p}}$⌉ data. This paper proposes an array method for cycle detection in discrete logarithms. The proposed method reduces the number of updates of stack memory by at least 73%. This is done by only updating the array when (xi<0.5xi-1)∩(xi<0.5(p-1)). The proposed array method undergoes the same number of modular calculation as stack method, but significantly reduces the number of updates and the execution time for array through the use of a binary search method.

A Search for Exoplanets around Northern Circumpolar Stars. IX. A Multi-Period Analysis of the M Giant HD 135438

  • Byeong-Cheol Lee;Jae-Rim Koo;Yeon-Ho Choi;Tae-Yang Bang;Beomdu Lim;Myeong-Gu Park;Gwanghui Jeong
    • Journal of The Korean Astronomical Society
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    • v.56 no.2
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    • pp.277-286
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    • 2023
  • It is difficult to distinguish the pure signal produced by an orbiting planetary companion around giant stars from other possible sources, such as stellar spots, pulsations, or certain activities. Since 2003, we have obtained radial (RV) data from evolved stars using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). Here, we report the results of RV variations in the binary star HD 135438. We found two significant periods: 494.98 d with eccentricity of 0.23 and 8494.1 d with eccentricity of 0.83. Considering orbital stability, it is impossible to have two companions in such close orbits with high eccentricity. To determine the nature of the changes in the RV variability, we analyzed indicators of stellar spot and stellar chromospheric activity to find that there are no signals related to the significant period of 494.98 d. However, we calculated the upper limits of rotation period of the rotational velocity and found this to be 478-536 d. One possible interpretation is that this may be closely related to the rotational modulation of an orbital inclination at 67-90 degrees. The other signal corresponding to the period of 8494.1 d is probably associated with a stellar companion orbiting the giant star. A Markov Chain Monte Carlo (MCMC) simulation considering a single companion indicates that HD 135438 system hosts a stellar companion with 0.57+0.017 -0.017 M with an orbital period of 8498 d.

Automatic Extraction of Eye and Mouth Fields from Face Images using MultiLayer Perceptrons and Eigenfeatures (고유특징과 다층 신경망을 이용한 얼굴 영상에서의 눈과 입 영역 자동 추출)

  • Ryu, Yeon-Sik;O, Se-Yeong
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.2
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    • pp.31-43
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    • 2000
  • This paper presents a novel algorithm lot extraction of the eye and mouth fields (facial features) from 2D gray level face images. First of all, it has been found that Eigenfeatures, derived from the eigenvalues and the eigenvectors of the binary edge data set constructed from the eye and mouth fields are very good features to locate these fields. The Eigenfeatures, extracted from the positive and negative training samples for the facial features, ate used to train a MultiLayer Perceptron(MLP) whose output indicates the degree to which a particular image window contains the eye or the mouth within itself. Second, to ensure robustness, the ensemble network consisting of multiple MLPs is used instead of a single MLP. The output of the ensemble network becomes the average of the multiple locations of the field each found by the constituent MLPs. Finally, in order to reduce the computation time, we extracted the coarse search region lot eyes and mouth by using prior information on face images. The advantages of the proposed approach includes that only a small number of frontal faces are sufficient to train the nets and furthermore, lends themselves to good generalization to non-frontal poses and even to other people's faces. It was also experimentally verified that the proposed algorithm is robust against slight variations of facial size and pose due to the generalization characteristics of neural networks.

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TIME-SERIES PHOTOMETRY OF VARIABLE STARS IN THE GLOBULAR CLUSTER NGC 288

  • Lee, Dong-Joo;Koo, Jae-Rim;Hong, Kyeongsoo;Kim, Seung-Lee;Lee, Jae Woo;Lee, Chung-Uk;Jeon, Young-Beom;Kim, Yun-Hak;Lim, Beomdu;Ryu, Yoon-Hyun;Cha, Sang-Mok;Lee, Yongseok;Kim, Dong-Jin;Park, Byeong-Gon;Kim, Chun-Hwey
    • Journal of The Korean Astronomical Society
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    • v.49 no.6
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    • pp.295-306
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    • 2016
  • We present the results of BV time-series photometry of the globular cluster NGC 288. Observations were carried out to search for variable stars using the Korea Microlensing Telescope Network (KMTNet) 1.6-m telescopes and a 4k pre-science CCD camera during a test observation from August to December, 2014. We found a new SX Phe star and confirmed twelve previously known variable stars in NGC 288. For the semi-regular variable star V1, we newly determined a period of 37.3 days from light curves spanning 137 days. The light-curve solution of the eclipsing binary V10 indicates that the system is probably a detached system. The pulsation properties of nine SX Phe stars were examined by applying multiple frequency analysis to their light curves. We derived a new Period-Luminosity (P-L) relation, ${\langle}M_V{\rangle}=-2.476({\pm}0.300){\log}P-0.354({\pm}0.385)$, from six SX Phe stars showing the fundamental mode. Additionally, the period ratios of three SX Phe stars that probably have a double-radial mode were investigated; $P_{FO}/P_F=0.779$ for V5, $P_{TO}/P_{FO}=0.685$ for V9, $P_{SO}/P_{FO}=0.811$ for V11. This paper is the first contribution in a series assessing the detections and properties of variable stars in six southern globular clusters with the KMTNet system.

Design and Implementation of ASTERIX Parsing Module Based on Pattern Matching for Air Traffic Control Display System (항공관제용 현시시스템을 위한 패턴매칭 기반의 ASTERIX 파싱 모듈 설계 및 구현)

  • Kim, Kanghee;Kim, Hojoong;Yin, Run Dong;Choi, SangBang
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.3
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    • pp.89-101
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    • 2014
  • Recently, as domestic air traffic dramatically increases, the need of ATC(air traffic control) systems has grown for safe and efficient ATM(air traffic management). Especially, for smooth ATC, it is far more important that performance of display system which should show all air traffic situation in FIR(Flight Information Region) without additional latency is guaranteed. In this paper, we design a ASTERIX(All purpose STructured Eurocontrol suRveillance Information eXchange) parsing module to promote stable ATC by minimizing system loads, which is connected with reducing overheads arisen when we parse ASTERIX message. Our ASTERIX parsing module based on pattern matching creates patterns by analyzing received ASTERIX data, and handles following received ASTERIX data using pre-defined procedure through patterns. This module minimizes display errors by rapidly extracting only necessary information for display different from existing parsing module containing unnecessary parsing procedure. Therefore, this designed module is to enable controllers to operate stable ATC. The comparison with existing general bit level ASTERIX parsing module shows that ASTERIX parsing module based on pattern matching has shorter processing delay, higher throughput, and lower CPU usage.

Invariant Classification and Detection for Cloth Searching (의류 검색용 회전 및 스케일 불변 이미지 분류 및 검색 기술)

  • Hwang, Inseong;Cho, Beobkeun;Jeon, Seungwoo;Choe, Yunsik
    • Journal of Broadcast Engineering
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    • v.19 no.3
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    • pp.396-404
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    • 2014
  • The field of searching clothing, which is very difficult due to the nature of the informal sector, has been in an effort to reduce the recognition error and computational complexity. However, there is no concrete examples of the whole progress of learning and recognizing for cloth, and the related technologies are still showing many limitations. In this paper, the whole process including identifying both the person and cloth in an image and analyzing both its color and texture pattern is specifically shown for classification. Especially, deformable search descriptor, LBPROT_35 is proposed for identifying the pattern of clothing. The proposed method is scale and rotation invariant, so we can obtain even higher detection rate even though the scale and angle of the image changes. In addition, the color classifier with the color space quantization is proposed not to loose color similarity. In simulation, we build database by training a total of 810 images from the clothing images on the internet, and test some of them. As a result, the proposed method shows a good performance as it has 94.4% matching rate while the former Dense-SIFT method has 63.9%.

Systematic approaches to identify functional genes using the FOX-hunting system in Chinese cabbage (FOX hunting system을 이용한 배추 기능유전자 탐색)

  • Lee, In-Hoo;Jung, Yu-Jin;Park, Jong-In;Nou, Ill-Sup;Kang, Kwon-Kyoo
    • Journal of Plant Biotechnology
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    • v.37 no.2
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    • pp.174-185
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    • 2010
  • Full-length cDNAs are essential for the correct annotation of genomic sequences and for the functional analysis of genes and their products. To elucidate the functions of a large population of Chinese cabbage (Brassica rapa) genes and to search efficiently for agriculturally useful genes, we have been taking advantage of the full-length cDNA Over-eXpresser (FOX) gene hunting system. With oligo dT column it purify the each mRNA from the flower organs, leaf and stem tissue. And about 120,000 cDNAs from the library were transformed into $\lambda$-pFLCIII-F vector. Of which 115,000 cDNAs from the library were transformed into T-DNA binary vector, pBigs for transformation study. We used normalized full-length cDNA and introduced each cDNA into Arabidopsis by in planta transformation. Full-length Chinese cabbage cDNAs were expressed independently under the CaMV 35S promoter in Arabidopsis. Selfed seeds were harvested from transgenic Arabidopsis. We had selected 2,500 transgenic plants by hygromycin antibiotic tolerant test, and obtained a number of transgenic mutants. Each transgenic Arabidopsis was investigated in morphological changes, fertility and leaf colour. As a result, 285 possible morphological mutants were identified. Introduced cDNA was isolated by PCR amplification of the genomic DNA from the transgenic mutants. Sequencing result and BLAST analysis showed that most of the introduced cDNA were complete cDNAs and functional genes. Also, we examined the effect of Bromelain on enhancing resistance to soft rot in transgenic Chinese cabbage 'Osome'. The bromelain gene identified from FOX hunting system was transformed into Chinese cabbage using Agrobacterium methods. Transformants were screened by PCR, then RT-PCR and real time PCR were performed to analyze gene expression of cysteine protease in the T1 and T2 generations. The anti-bacterial activity of bromelain was tested in Chinese cabbages infected with soft rot bacteria. The results showed that the over-expressed bromelain gene from pineapple conferred enhanced resistance to soft rot in Chinese cabbage.

Using Numerical Maps to Select Solar Panel Installation Sites no Expressway Slopes (수치지도를 이용한 고속국도 주변 태양광 패널 설치 대상지 선정)

  • Jung, Jaehoon;Kim, Byungil
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.5
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    • pp.71-77
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    • 2016
  • Solar energy is a viable source to replace fossil fuels. However, challenges associated with site selection for solar panel installation inhibit the uptake of solar energy systems. Expressway slopes offer a potentially attractive alternative for solar panel installation for the following reasons: expressway slopes are vacant public sites, they are abundant (about 4,193km in South Korea), and they are linear in nature. Traditoinally when selecting sites for solar systems conventional surveying methods are employed. Unfortunately, these methods can be dangerous, time consuming, and labor intensive. To overcome these limitations of conventional site selection methodologies, we propose an automated approach using numerical maps. First, contour and expressway polylines are extracted separately from numeric maps. The extracted contour lines are then converted into a digital terrain model; this is used to calculate aspect and slope information. Next, the extracted expressway lines are projected onto a binary image and refined to recover the disconnections, and then applied to create a buffer zone to narrow the search space. Finally, all data sets are overlaid to identify candidate sites for solar panel systems and are visually verified through comparisons with aerial photos.

Optimization of Post-Processing for Subsequence Matching in Time-Series Databases (시계열 데이터베이스에서 서브시퀀스 매칭을 위한 후처리 과정의 최적화)

  • Kim, Sang-Uk
    • The KIPS Transactions:PartD
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    • v.9D no.4
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    • pp.555-560
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    • 2002
  • Subsequence matching, which consists of index searching and post-processing steps, is an operation that finds those subsequences whose changing patterns are similar to that of a given query sequence from a time-series database. This paper discusses optimization of post-processing for subsequence matching. The common problem occurred in post-processing of previous methods is to compare the candidate subsequence with the query sequence for discarding false alarms whenever each candidate subsequence appears during index searching. This makes a sequence containing candidate subsequences to be accessed multiple times from disk, and also have a candidate subsequence to be compared with the query sequence multiple times. These redundancies cause the performance of subsequence matching to degrade seriously. In this paper, we propose a new optimal method for resolving the problem. The proposed method stores ail the candidate subsequences returned by index searching into a binary search tree, and performs post-processing in a batch fashion after finishing the index searching. By this method, we are able to completely eliminate the redundancies mentioned above. For verifying the performance improvement effect of the proposed method, we perform extensive experiments using a real-life stock data set. The results reveal that the proposed method achieves 55 times to 156 times speedup over the previous methods.

Oedipa's Quest and Two Americas (에디파의 탐구와 두 개의 미국)

  • Son, Dongchul
    • English & American cultural studies
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    • v.9 no.1
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    • pp.273-295
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    • 2009
  • As Oedipa Mass, the heroine of Thomas Pynchon's The Crying of Lot 49, is apparently associated with Oedipus, the hero in Sophocles' tragedy, this paper aims to show some of their similarities in quest theme and plot development as well as in the use of dramatic irony. Oedipus the King opens with a priest's pleas to relieve the Theban people from a plague and the king's promise to rid its cause by avenging the murder of the former king, as told by the oracle. Lot 49 begins as a Los Angeles law firm informs Oedipa that she is named as the executrix in her former lover Inverarity's will to sort out the mogul's estate. Ironically, however, Oedipus' investigation reveals himself to be the very cause of the national disaster, the murderer for whom he searched. Likewise, Oedipa starts her inquiry dedicating herself to make sense out of what Inverarity had left behind, only to find that the legacy was America. Sophocles and Pynchon both employ dramatic irony to provide a controlling principle for plot development in their works. In Oedipus the King, Sophocles creates mounting tension as well as distance between the reader's knowledge and the protagonist's ignorance, compressing the play's action into the moment that Oedipus discovers his real identity. For dramatic irony, however, Pynchon tends to work through authorial comments and utilize allegorical meanings of the characters' names, directing his novel at illuminating Oedipa's discovery of Inverarity's legacy as well as the meaning of Tristero, an underground postal service system. Unlike Oedipus the King that proceeds on a single line of action, Lot 49 develops in esoteric, multi-layered allusions and intricately-interrelated double strains involving Oedipa's roles as executrix and quester. At the end of Sophocles' tragedy, Oedipus stabs his eyes and decides to live in exile, realizing that, blinded, he begot his children through his mother; Oedipa comes to a painful realization that she allowed her former lover to create death-orienting America without her diversity and moral system in old times. As Oedipa now discovers herself through her search for Tristero, her tragic spirit lies in her determination to confront her binary choices between two Americas: transcendence or entropy, the Tristero possibility or Inverarity's America. Ultimately, Oedipa tries to find who will be the bidder for the Tristero forged stamps designated as lot 49, awaiting the auctioneer's cry and the "crying" of a new-born America.