• 제목/요약/키워드: complex multiplication

검색결과 84건 처리시간 0.025초

Reducing Cybersecurity Risks in Cloud Computing Using A Distributed Key Mechanism

  • Altowaijri, Saleh M.
    • International Journal of Computer Science & Network Security
    • /
    • 제21권9호
    • /
    • pp.1-10
    • /
    • 2021
  • The Internet of things (IoT) is the main advancement in data processing and communication technologies. In IoT, intelligent devices play an exciting role in wireless communication. Although, sensor nodes are low-cost devices for communication and data gathering. However, sensor nodes are more vulnerable to different security threats because these nodes have continuous access to the internet. Therefore, the multiparty security credential-based key generation mechanism provides effective security against several attacks. The key generation-based methods are implemented at sensor nodes, edge nodes, and also at server nodes for secure communication. The main challenging issue in a collaborative key generation scheme is the extensive multiplication. When the number of parties increased the multiplications are more complex. Thus, the computational cost of batch key and multiparty key-based schemes is high. This paper presents a Secure Multipart Key Distribution scheme (SMKD) that provides secure communication among the nodes by generating a multiparty secure key for communication. In this paper, we provide node authentication and session key generation mechanism among mobile nodes, head nodes, and trusted servers. We analyzed the achievements of the SMKD scheme against SPPDA, PPDAS, and PFDA schemes. Thus, the simulation environment is established by employing an NS 2. Simulation results prove that the performance of SMKD is better in terms of communication cost, computational cost, and energy consumption.

A Mutation of a Putative NDP-Sugar Epimerase Gene in Ralstonia pseudosolanacearum Attenuates Exopolysaccharide Production and Bacterial Virulence in Tomato Plant

  • Hyoung Ju Lee;Sang-Moo Lee;Minseo Choi;Joo Hwan Kwon;Seon-Woo Lee
    • The Plant Pathology Journal
    • /
    • 제39권5호
    • /
    • pp.417-429
    • /
    • 2023
  • Ralstonia solanacearum species complex (RSSC) is a soil borne plant pathogen causing bacterial wilt on various important crops, including Solanaceae plants. The bacterial pathogens within the RSSC produce exopolysaccharide (EPS), a highly complicated nitrogencontaining heteropolymeric polysaccharide, as a major virulence factor. However, the biosynthetic pathway of the EPS in the RSSC has not been fully characterized. To identify genes in EPS production beyond the EPS biosynthetic gene operon, we selected the EPS-defective mutants of R. pseudosolanacearum strain SL341 from Tn5-inserted mutant pool. Among several EPSdefective mutants, we identified a mutant, SL341P4, with a Tn5-insertion in a gene encoding a putative NDP-sugar epimerase, a putative membrane protein with sugar-modifying moiety, in a reverse orientation to EPS biosynthesis gene cluster. This protein showed similar to other NDP-sugar epimerases involved in EPS biosynthesis in many phytopathogens. Mutation of the NDP-sugar epimerase gene reduced EPS production and biofilm formation in R. pseudosolanacearum. Additionally, the SL341P4 mutant exhibited reduced disease severity and incidence of bacterial wilt in tomato plants compared to the wild-type SL341 without alteration of bacterial multiplication. These results indicate that the NDP-sugar epimerase gene is required for EPS production and bacterial virulence in R. pseudosolanacearum.

정보 증류 및 재귀적인 방식을 이용한 심층 학습법 기반 경량화된 초해상도 네트워크 (Lightweight Super-Resolution Network Based on Deep Learning using Information Distillation and Recursive Methods)

  • 우희조;심지우;김응태
    • 방송공학회논문지
    • /
    • 제27권3호
    • /
    • pp.378-390
    • /
    • 2022
  • 최근 심층 합성 곱 신경망 학습의 발전에 따라 단일 영상 초해상도에 적용되는 심층 학습 기법들을 좋은 성과를 보여주고 있으며 깊은 네트워크의 강한 표현 능력으로 저해상도 영상과 고해상도 영상 사이의 복잡한 비선형 매핑이 가능해졌다. 하지만 과도한 합성곱 신경망의 사용으로 인해 증가하는 파라미터와 연산량으로 실시간 또는 저전력 장치에 적용하는데 제한이 있다. 본 논문은 정보 증류 방식을 이용하여 계층적인 특징을 조금씩 추출해내는 블록을 재귀적인 방식으로 사용하며 고주파수 잔여 정제 블록을 통해 더 정확한 고주파수 성분을 만들어 성능을 향상시키는 경량화된 네트워크인 Recursive Distillation Super Resolution Network (RDSRN) 를 제안한다. 제안하는 네트워크는 RDN과 비교했을 때 비슷한 화질의 영상을 복원하며 약 32배 적은 파라미터와 약 10배 적은 연산량을 가지고 약 3.5배 더 빠르게 영상을 복원하며 기존 경량화 네트워크 CARN과 비교했을 때 약 2.2배 적은 파라미터와 약 1.8배 빠른 처리시간으로 평균 0.16dB 더 좋은 성능을 만들어 냄을 확인 하였다.

수학사에 기초한 벡터의 내적과 외적의 연결 (Connecting the Inner and Outer Product of Vectors Based on the History of Mathematics)

  • 오택근
    • 대한수학교육학회지:수학교육학연구
    • /
    • 제25권2호
    • /
    • pp.177-188
    • /
    • 2015
  • 본 논문은 평면과 공간에서 두 벡터의 곱에 대한 역사적 발달 과정을 살펴보고, 이를 바탕으로 벡터의 내적과 외적을 연결하기 위한 교육적 시사점을 도출하였다. 역사적 분석의 결과, 평면에서 방향이 다른 두 선분의 곱을 정의하려는 노력은 두 선분의 길이의 곱과 방향각의 합이라는 기하학적 의미와 함께 복소수의 연산 규칙을 확립함으로써 복소수를 수학적 대상으로 승인하는 계기를 제공하였음을 확인하였다. 또한 3차원 공간에서 방향이 다른 두 선분의 곱을 정의하려는 노력은 사원수의 도입을 이끌었으며, 사원수의 곱으로 나타나는 실수부분과 벡터부분이 각각 벡터의 내적과 외적의 현대적인 정의로 발전하였음을 확인하였다. 이러한 분석 결과를 토대로 기하학적 관점에서 벡터의 내적과 외적을 각각 다른 방식으로 정의하여 서로 관련이 없는 것으로 인식하도록 만드는 현재의 전개방식에 대해 반성하고, 이 두 곱을 연결시키기 위한 한 가지 방안을 제시하였다.

Overcoming the challenges of Monte Carlo depletion: Application to a material-testing reactor with the MCS code

  • Dos, Vutheam;Lee, Hyunsuk;Jo, Yunki;Lemaire, Matthieu;Kim, Wonkyeong;Choi, Sooyoung;Zhang, Peng;Lee, Deokjung
    • Nuclear Engineering and Technology
    • /
    • 제52권9호
    • /
    • pp.1881-1895
    • /
    • 2020
  • The theoretical aspects behind the reactor depletion capability of the Monte Carlo code MCS developed at the Ulsan National Institute of Science and Technology (UNIST) and practical results of this depletion feature for a Material-Testing Reactor (MTR) with plate-type fuel are described in this paper. A verification of MCS results is first performed against MCNP6 to confirm the suitability of MCS for the criticality and depletion analysis of the MTR. Then, the dependence of the effective neutron multiplication factor to the number of axial and radial depletion cells adopted in the fuel plates is performed with MCS in order to determine the minimum spatial segmentation of the fuel plates. Monte Carlo depletion results with 37,800 depletion cells are provided by MCS within acceptable calculation time and memory usage. The results show that at least 7 axial meshes per fuel plate are required to reach the same precision as the reference calculation whereas no significant differences are observed when modeling 1 or 10 radial meshes per fuel plate. This study demonstrates that MCS can address the need for Monte Carlo codes capable of providing reference solutions to complex reactor depletion problems with refined meshes for fuel management and research reactor applications.

21세기 패션디자인에 나타난 탈정형적 공간 표현에 관한 연구 (A Study on Post-formal Spatial Expression in 21 st Century Fashion Design)

  • 양희영;김소영
    • 복식
    • /
    • 제58권8호
    • /
    • pp.91-105
    • /
    • 2008
  • Spatial multiplication phenomenon, expressed through de-constructive trend since the late of 20C, have got changed existing fixed and dis-variable space to smooth, fluid, and changeable space. Ex-form and fluidity of new spatial paradigm have been focused through lots of scientific theories studied between digital thought and indeterminacy and rankless nature phenomena. In 21C fashion, indeterminate and irregular form and space have been crested continuously, which could not explain simply according as the fluidity theory Different from the space crested for multi-function and multipurpose, this is revealed the characteristics of chaosmos that communizes the order and the disorder, deconstruction and creation. Ex-formal space of fashion have shown the relationship of de-centerizing, de-territorial, and do-structural phenomenon among different fashion elements. This paper intends to understand the concept of ex-form, and study expressive manners of ex-formal space of 21C fashion, and conclusion as follows. 1) Overlap changes single space of fashion to multi-layered space through the repeat system of pleats, origami, and folding. 2) Ex-gravity expressed in deviation of the gravity acting vertical direction, for example, twisting, curve, winding, portion. 3) Morphing is shown the change process from single fixed form to different complex form. 4) Blurring is expressed in re-combination and re-arrangement among elements of fashion. 5) Blob shows hybrid fashion space through the liberal compounding and separation of a lot of different elements.

전시공간에서의 촉지적(Haptic)연출 방법에 대한 연구 - 체험전시 공간 중심으로 - (A Study on Haptic Presentation Methods in the Experience Exhibition Spaces - With Experience Exhibition Space -)

  • 조민화
    • 한국실내디자인학회논문집
    • /
    • 제24권6호
    • /
    • pp.229-239
    • /
    • 2015
  • The 21st century is a multiplication age and social and cultural phenomena have become diverse and peoples' desires and individuality have become important. Accordingly, the sensibility that reflects human taste is also required in the exhibition space. The exhibitions in this age induce the direct cognition of senses or take interactive forms that contact diverse media and react. The purpose of this research is to define the concept of haptic presentation method in which the audience perceive in the exhibition space by themselves and the visual elements spread into other senses and perceive complexly, and to present the directional nature. To conduct this research, first, this researcher recognized that haptic sensory experiential research by analyzing the roles and transition history of exhibition space is needed for the present age Second, based on philosophical theories, four haptic sensory expression characteristics (medium nature, experiential nature, attractiveness, sensitiveness) were derived by substituting Giles Deleuze's four haptic spatial characteristics (grasping short distance, dispersed gaze, cognition of bodily movement, formation of synesthesia through complex senses) and six formative factors of exhibition space (space, form, size, light, quality of materials, and color). And the effective exhibition presentation methods were analyzed through six cases of experiential exhibition spaces. Accordingly, what matters in the experiential exhibition space is to produce the four characteristics: medium nature, experientiality, attractiveness, and sensitiveness in equilibrium. It is necessary for the designers to reflect it appropriately in producing so that the audience can think and experience by themselves. Accordingly, in this thesis, it could be seen that to produce the haptic production characteristics in the experiential exhibition space in equilibrium is the important factor in the experiential exhibition space. In conclusion, experiences in the exhibition space should be approached with the transcendental haptic presentation method by which even the space of actually unexperienced cognition can be expanded and experienced through the metastasis and tension of various senses. Also, researches on such senses should be developed continuously, and this researcher expects that this will become a stimulant to present a new directivity.

LQ 제어와 근의 이동범위를 이용한 중근의 극배치 방법 (Pole Placement Method of a Double Poles Using LQ Control and Pole's Moving-Range)

  • 박민호
    • 한국산학기술학회논문지
    • /
    • 제21권1호
    • /
    • pp.20-27
    • /
    • 2020
  • 일반적으로 비선형 시스템은 1차와 2차 시스템의 곱의 형태로 선형화되며, 시스템은 실근, 중근, 서로 다른 두 실근, 복소근의 4종류의 근을 가진다. 이 논문은 시스템이 가지는 4가지 근 중에서 조단블록을 갖는 중근을 복소근으로 이동시키는 LQ 제어의 가중행렬과 제어법칙을 설계하는 방법에 관한 것이다. 상태가중행렬을 제한 조건으로 하고 성능지수함수를 최소화하는 LQ 제어는 시스템의 안정성을 보장하고 시스템의 근을 이동시키는 극배치 기능을 가지고 있다. 그렇지만 이 방법은 시행착오 방법으로 설계 변수인 가중행렬을 설정하고, 이동되는 근의 위치를 정확히 지정할 수 없는 문제가 있다. 이 문제를 해결하기 위해 해밀토니안 시스템의 특성방정식을 대각행렬의 제어가중행렬과 삼각함수로 표현된 상태가중행렬을 이용하여 기술한다. 이동할 복소근이 이 특성방정식의 근이라는 조건에서 중근과 상태가중행렬의 관계식(𝜌, 𝜃)을 유도하고 상태가중행렬이 양의 반한정행렬이라는 조건에서 중근의 이동범위를 구하고, 좌표평면에 도시한다. 그려진 중근의 이동범위에서 복소근을 선택하여 관계식에 대입하여 상태가중행렬을 계산하고, 이것에서 제어법칙이 구한다. 예제에서 3차 시스템의 중근을 이동시키는 제어법칙의 설계과정을 통해 제안한 방법의 타당성을 확인하였다.

저출력 레이저 조사 백서구강점막 창상부 Langerhans 세포에 미치는 영향에 관한 실험적 연구 (Experimental study on the effect of low energy laser irradiation in Langerhans cell of Lanaged rat oral mucosa)

  • 조재오
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • 제15권3호
    • /
    • pp.217-228
    • /
    • 1993
  • The purpose or this study was to observe the histological alteration of Langerhans cells on wound healing process in applying low energy laser irradiation. For this study, 50 Spraque-Dewly rats, weighing 150Gm or more were devided into control, experimental control group(0), 47.5Hz(1), 190Hz(3), 380Hz(5), 760Hz(7), lased group. All the experimental animals were made excision wound on buccal mucosa, 2mm depth, and lased with stoma laser (904nm, semconductor type ASGaAI, Sedalac France) 47.5Hz, 380Hz, 960Hz, 3minutes one time respectively except experimental control group. After the experiment, experimental animals were sacrificed after 24hours, 48hours, 72hours on each. Taken specimens were embedden in paraffin, sectioned 6-8u in thickness. And the langerhans cell were detected using ant S-100 protein antibody, and histochemically processed with Avidin Biotin complex method. All the Langerhan cells were calculated under light microspe in 400 multiplication field and standard deviation, probability test between each group were evaluated using statistical analysis system(S.A.S)program. Following results were obtained. 1. Langerhan cells were increased in experimental control group compared to that in control group(P<0.01). 2. 24hour after experiments, Langerhans cell were decreased compare to that in control group and control experimental group 5, 1, 3. Probability test shows significance between control experimental and 5, 1, 3 group on a =0.05 range. 3. 48our after experiment, Langerhans cells were decreased compare to that on experimental control group, and probability test shows significance between control experimental and 3, 7, 5 group an a=0.05 range. 4. 72hour after experiments, Langerhans cells were decreased compare to that on experimental control group and probability test on group comparison shows significance between control experimental and 1, 5 and 1 between 3, 7 between 3, and 5, between 7, respeilively on a=0.05 range. 5. Langerhans cells number in experimental group were decreased compare to that on experimental control group in applying laser irradiation.

  • PDF

삼중 행렬 곱셈의 효율적 연산 (An Efficient Computation of Matrix Triple Products)

  • 임은진
    • 한국컴퓨터정보학회논문지
    • /
    • 제11권3호
    • /
    • pp.141-149
    • /
    • 2006
  • 본 논문에서는 회로 설계 소프트웨어에서 사용되는 primal-dual 최적화 문제의 해를 구하기 위해 필요한 삼중 행렬 곱셈 연산 ($P=AHA^{t}$)의 성능 개선에 관하여 연구하였다. 이를 위하여 삼중 행렬 곱셈 연산의 속도를 개선하기 위하여 기존의 2단계 연산 방법을 대신하여 1단계 연산 방법을 제안하고 성능을 분석하였다. 제안된 방법은 희소 행렬 H의 블록 대각 구조의 특성을 이용하여 부동 소숫점 연산량을 감소시킴으로써 성능 개선을 이루었으며 더불어 메모리 사용량도 기존 방법에 비하여 50% 이하로 감소하였다. 그 결과 Intel Itanium II 플랫폼에서 기존 2단계 연산 방법과 비교하여 속도 면에서 주어진 실험 데이터 집합에 대하여 평균 2.04 의 speedup을 얻었다. 또한 본 논문에서는 플랫폼의 메모리 지연량과 예측된 캐쉬 미스율을 이용한 성능 모델링을 통하여 이와 같은 성능 개선 수치의 가능 범위를 보이고 실측된 성능개선을 평가하였다. 이와 같은 연구는 희소 행렬의 성능 개선 연구를 기본 연산이 아닌 복합 연산에 적용하는 연구로써 큰 의미가 있다.

  • PDF