• 제목/요약/키워드: HiLow

검색결과 534건 처리시간 0.035초

6LoWPAN의 계층적 라우팅 기법에서 이웃 노드 리스트를 이용한 Short-cut 라우팅 알고리즘 (Short-cut Routing Algorithm Using Neighbor Node List in Hierarchical Routing for 6LoWPAN)

  • 강문경;진교홍
    • 한국항행학회논문지
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    • 제11권3호
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    • pp.296-305
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    • 2007
  • 6LoWPAN에서 사용되는 계층적 라우팅 프로토콜인 HiLow는 적은 메모리 사용과 낮은 에너지 소모율을 보이지만 최적의 경로를 제공하지 못하는 단점이 있다. 본 논문에서는 HiLow 라우팅 알고리즘의 성능을 개선하기 위해서 계층적 라우팅 경로정보 뿐만 아니라 소스 노드 주위의 이웃 노드의 정보를 활용하여 데이터가 전달될 최적의 다음 홉(Next hop)을 결정하는 알고리즘을 제안하였다. 제안된 알고리즘은 컴퓨터 시뮬레이션을 통해 성능을 분석하였으며, 그 결과 홉 수, 전송되는 메시지 수 측면에서 많은 개선이 있음을 알 수 있었다.

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Explainable radionuclide identification algorithm based on the convolutional neural network and class activation mapping

  • Yu Wang;Qingxu Yao;Quanhu Zhang;He Zhang;Yunfeng Lu;Qimeng Fan;Nan Jiang;Wangtao Yu
    • Nuclear Engineering and Technology
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    • 제54권12호
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    • pp.4684-4692
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    • 2022
  • Radionuclide identification is an important part of the nuclear material identification system. The development of artificial intelligence and machine learning has made nuclide identification rapid and automatic. However, many methods directly use existing deep learning models to analyze the gamma-ray spectrum, which lacks interpretability for researchers. This study proposes an explainable radionuclide identification algorithm based on the convolutional neural network and class activation mapping. This method shows the area of interest of the neural network on the gamma-ray spectrum by generating a class activation map. We analyzed the class activation map of the gamma-ray spectrum of different types, different gross counts, and different signal-to-noise ratios. The results show that the convolutional neural network attempted to learn the relationship between the input gamma-ray spectrum and the nuclide type, and could identify the nuclide based on the photoelectric peak and Compton edge. Furthermore, the results explain why the neural network could identify gamma-ray spectra with low counts and low signal-to-noise ratios. Thus, the findings improve researchers' confidence in the ability of neural networks to identify nuclides and promote the application of artificial intelligence methods in the field of nuclide identification.

A novel reconstruction algorithm based on density clustering for cosmic-ray muon scattering inspection

  • Hou, Linjun;Zhang, Quanhu;Yang, Jianqing;Cai, Xingfu;Yao, Qingxu;Huo, Yonggang;Chen, Qifan
    • Nuclear Engineering and Technology
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    • 제53권7호
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    • pp.2348-2356
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    • 2021
  • As a relatively new radiation imaging method, the cosmic-ray muon scattering imaging technology can be used to prevent nuclear smuggling and is of considerable significance to nuclear safety. Proposed in this paper is a new reconstruction algorithm based on density clustering, aiming to improve inspection quality with better performance. Firstly, this new algorithm is introduced in detail. Then in order to eliminate the inequity of the density threshold caused by the heterogeneity of the muon flux in different positions, a new flux correction method is proposed. Finally, three groups of simulation experiments are carried out with the help of Geant4 toolkit to optimize the algorithm parameters, verify the correction method and test the inspection quality under shielded condition, and compare this algorithm with another common inspection algorithm under different conditions. The results show that this algorithm can effectively identify and locate nuclear material with low misjudging and missing rates even when there is shielding and momentum precision is low, and the threshold correcting method is universally effective for density clustering algorithms.

짧은 길이 전송선로를 가지는 Hi-Z Low-Z에 의한 마이크로스트립 필터 (Microstrip Filter by Means of Hi-Z Low-Z Having Short Length Transmission Lines)

  • 이봉수;이사원
    • 한국컴퓨터정보학회논문지
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    • 제3권3호
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    • pp.107-112
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    • 1998
  • 본 논문에서는 마이크로스트립 선로로 제작이 쉽고, 스터브를 사용한 필터보다 적은 공간을 차지하는 Hi-Z, Low-Z 필터를 사용하여 마이크로스트립 필터를 설계.제작하였다. 이 필터는 선로의 전기적 길이가 매우 짧은 경우. 즉 Bl<$\pi$/4의 조건에서, 저역통과기본형의 직렬 인덕터일 때 고 임피던스 선로부로 병렬 커패시터를 저 임피던스 선로부로 대치할 수 있다. 이렇게 대치된 각 단을 마이크로스트립 선로로 설계하기 위해 주어진 마이크로스트립의 실효 유전율을 구해서 각 단의 폭과 길이를 계산하고 필터 설계에 사용하였다. 또한, 설계된 필터를 Touchstone의 이론치와 제작된 필터의 실험치를 비교하여 응답특성을 분석하였다.

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유행동조성과 혁신성에 따른 소비자 세분화 및 준거대상 연구 (Consumer Segmentation of Clothing Products by Fashion Conformity/Innovativeness and Their Reference Groups)

  • 김한나;이은영
    • 한국의류학회지
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    • 제25권7호
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    • pp.1341-1352
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    • 2001
  • When segmenting consumers according to their fashion adoption behavior, it has been assumed that consumers' fashion conformity and innovativeness characteritics are negatively correlated. The purpose of this study was to examine the relationship between conformity and innovativeness and that these two attributes exist independently. The research problems of this study were to segment consumers according to the degrees of conformity and innovativeness, and to identify differences in reference groups and clothing purchasing behavior among the segments. The results of the empirical study showed that the fashion conformity and innovativeness were in and innovativeness; High conformity/High innovativeness group(HC/HI), High conformity/Low innovativeness group (HC/LI), Low conformity/High innovativeness group(LC/HI?, and Low conformity/Low innovativeness group (LC/LI). When the groups were compared in their reference groups and purchasing behavior, it was found out that HC groups were more influenced by reference groups than LC groups. When HC/LI and HC/HI groups were compared, HC/LI group was more influenced by their parents and siblings, while HC/HI group was more influenced by upper class and celebrities. Both groups were mostly influenced by friends and desirable passengers on the street. Friends and passengers were most influential to LC groups also, even though they were less influenced than HC groups. In conclusion, the fashion conformity and innovativeness were found to exist in different dimensions consisting dual structure. Thus, retailers and marketers can make their strategies more successfully if they use these two characteristics separately when segmenting consumers.

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Comparison of the Performance of MiSeq and HiSeq 2500 in a Microbiome Study

  • Na, Hee Sam;Yu, Yeuni;Kim, Si Yeong;Lee, Jae-Hyung;Chung, Jin
    • 한국미생물·생명공학회지
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    • 제48권4호
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    • pp.574-581
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    • 2020
  • Next generation sequencing is commonly used to characterize the microbiome structure. MiSeq is commonly used to analyze the microbiome due to its relatively long read length. However, recently, Illumina introduced the 250x2 chip for HiSeq 2500. The purpose of this study was to compare the performance of MiSeq and HiSeq in the context of oral microbiome samples. The MiSeq Reagent Kit V3 and the HiSeq Rapid SBS Kit V2 were used for MiSeq and HiSeq 2500 analyses, respectively. Total read count, read quality score, relative bacterial abundance, community diversity, and relative abundance correlation were analyzed. HiSeq produced significantly more read sequences and assigned taxa compared to MiSeq. Conversely, community diversity was similar in the context of MiSeq and HiSeq. However, depending on the relative abundance, the correlation between the two platforms differed. The correlation between HiSeq and MiSeq sequencing data for highly abundant taxa (> 2%), low abundant taxa (2-0.2%), and rare taxa (0.2% >) was 0.994, 0.860, and 0.416, respectively. Therefore, HiSeq 2500 may also be compatible for microbiome studies. Importantly, the HiSeq platform may allow a high-resolution massive parallel sequencing for the detection of rare taxa.

HI Shells and Supershells in the I-GALFA HI 21-cm Line Survey

  • 박금숙;구본철
    • 천문학회보
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    • 제36권2호
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    • pp.112.2-112.2
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    • 2011
  • We carry out a systematic study of HI shells and supershells in the first Galactic quadrant (l = $32^{\circ}$ to $77^{\circ}$, b = $-10^{\circ}$ to $10^{\circ}$) using the "Inner-Galaxy Arecibo L-band Feed Array (I-GALFA)" HI 21-cm survey data. The high-resolution (3.'4) and high sensitivity (0.2 K) of the survey provide us an opportunity to exploit the true nature of the sources detected in previous low-resolution studies and also to detect faint and/or small shells that were not detectable before. Our work is composed of three parts: (1) confirm the objects in the low-resolution (about 30') catalog of Heiles (1979), (2) search for fast-expanding HI shells associated with Galactic supernova remnants (SNRs), and (3) search for new shell structures. Among the 21 Heiles' supershells in the I-GALFA survey area, we confirm fourteen. The high resolution data reveal their complex morphology, and provide direct evidence for expansion in some sources. Among the 39 Galactic SNRs in the survey area, we find five with associated fast expanding HI shells, which is consistent with previous results. A remarkable result from the SNR study is the detection of HI gas at very high negative velocities in the SNR W44 that should be from the approaching part of the HI expanding shell. This is the first time to detect both the approaching and receding sides of an expanding shell in HI 21-cm emission line in SNRs. We have found 33 new shell candidates of angular sizes ranging from 0.5 to 6.5 degrees, half of which appear to be expanding. We summarize these results and discuss some individual interesting objects in detail.

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초신성 잔해 PKS0607+17 및 HII 영역 S261의 HI 21CM선 관측 연구 (HI 21CM OBSERVATIONS OF THE SUPERNOVA REMNANT PKS0607+17 AND THE HII REGION S261)

  • 장명순;구본철
    • 천문학논총
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    • 제12권1호
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    • pp.63-84
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    • 1997
  • We carried out high-resolution(FWHM=3' .3) HI 21 cm observations of the supernova remnant(SNR) PKS0607+17 and HII region S261 using Arecibo 305-m telescope. The observation was to investigate whether the high-velocity(HV) gas detected in the southern area of PKS0607+17 by Koo & Heiles(1991) is physically associated with the SNR or not. The velocity of the HV gas ranges from +64 km/s to +87 km/s, which is difficult to result from the Galactic rotation. The HV gas could be the gas accelerated by supernova blast wave. However, because the observation of Koo and Heiles(1991) was carried out using Hat Creek radio telescope(FWHM $\simeq$ 36'), the association of the HV gas with the SNR could not be investigated. Using the Arecibo HI 21cm data, we have found that the HV gas appears m the southern part of the SNR and its velocity ranges from +61 km/s to +77 km/s. But the HV gas is scattered m the whole field, not only toward PKS0607+17 but also outside the SNR Accordingly the HV gas is probably not associated with the SNR, but is accidentally aligned along the same line of sight toward the SNR. Instead we have found that HI clouds at low velocities could be possibly associated with the SNR. In Arecibo HI 21cm channel maps the HI gas seems to surround the southern boundary of the SNR at $V_{LSR}$ = +19.6 ~ +40.2 km/s. But because the region of the Arecibo HI 21cm observation is not wide enough to examine the HI gas distribution, we investigated this area using the Berkely low-latitude HI survey data(Weaver & Williams 1974) too. There we found HI gas surrounding the radio continuum boundary of PKS0607+17 at $V_{LSR}$ = +21.6 ~ +258 km/s. It is possible that this HI gas is associated with the SNR, in which case, the velocity of the SNR $V_o$ $\simeq$ +26 km/s, its distance d $\simeq$ 12.5 kpc and its radius R $\simeq$ 145 pc. If we assume that the expansion velocity is ~10 km/s, then the age of the SNR is $\sim4.4\times10^6$ years. PKS0607+17 could be one of the oldest SNRs in the Galaxy. We also studied HI propertities of the HII region S261, which is $\sim1^{\circ}$ away from PKS0607+17. There has been no high-resolution m 21 cm observational study on S261. We discovered HI cloud located at the north-eastern part of S261 at $V_{LSR}$ = +5 km/s ~ +10 km/s, which is possibly associated with the HII region. The central velocity of the HI cloud $V_{LSR}$ = +7.2 km/s and the corresponding distance d = 1.5 kpc. This velocity is comparable to the radio recombination line velocities.

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HiPi-bus 구조의 다중 프로세서 시스템에서의 잠금장치 (A Lock Mechanism for HiPi-bus Based Multiprocessor Systems)

  • 윤용호;임인칠
    • 전자공학회논문지B
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    • 제30B권2호
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    • pp.33-43
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    • 1993
  • Lock mechanism is essential for synchronization on the multiprocessor systems. Lock mechanism needs to reduce the time for lock operation in low lock contention. Lock mechanism must consider the case of the high lock contention. The conventional lock control scheme in memory results in the increase of bus traffic and memory utilization in lock operation. This paper suggests a lock scheme which stores the lock data in cache and manages it efficiently to reduce the time spent in lock operation when the lock contention is low on a multiprocessor system built on HiPi-bus(Highly Pipelined bus). This paper also presents the design of the HIPi-CLOCK (Highly Pipelined bus Cache LOCK mechanism) which transfere the data from on cache to another when the lock contention is high. The designed simulator compares the conventional lock scheme which controls the lock in memory with the suggested HiPi-CLOCK scheme in terms of the RMW(Read-Modify-Write) operation time using simulated trace. It is shown that the suggested lock control scheme performance is over twice than that of the conventional method in low lock contention. When the lock contention is high, the performance of the suggested scheme increases as the number of the shared lock data increases.

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Shell Candidates from I-GALFA HI Survey

  • Park, Geum-Sook;Koo, Bon-Chul
    • 천문학회보
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    • 제35권2호
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    • pp.68.2-68.2
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    • 2010
  • Diffuse interstellar atomic hydrogen (HI) gases are easily shaped into shell-like features by energetic processes such as stellar winds and supernova explosions. The physical characteristics and the Galactic distribution of HI shells and shell-like structures, therefore, are closely related to those of the energy sources. Recently, Inner-Galaxy Arecibo L-band Feed Array (I-GALFA) low-latitude HI survey has been completed. I-GALFA HI survey covers the central part of the first quadrant ($31^{\circ}{\lesssim}1{\lesssim}77^{\circ}$ at b = $0^{\circ}$, ${\mid}b{\mid}\lesssim\;12^{\circ}$) with spatial and velocity resolutions of 3.35′and 0.184 km/s, respectively. The high-angular and high-velocity resolutions enable in-depth investigation of HI shells including the ones of smaller angular sizes. We have found 36 shell candidates with the naked eye. Their angular sizes are distributed from $\sim0.4^{\circ}$ to $\sim12^{\circ}$. About sixteen of them appear to be expanding. We examine associated features at other wavebands and discuss their origin.

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