• 제목/요약/키워드: Phase advance control

검색결과 52건 처리시간 0.025초

DDoS 공격에 대한 선제적 침입 탐지·차단 방안 (A Method for Preemptive Intrusion Detection and Protection Against DDoS Attacks)

  • 김대환;이수진
    • 한국IT서비스학회지
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    • 제15권2호
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    • pp.157-167
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    • 2016
  • Task environment for enterprises and public institutions are moving into cyberspace-based environment and structing the LTE wireless network. The applications "App" operated in the LTE wireless network are mostly being developed with Android-based. But Android-based malwares are surging and they are the potential DDoS attacks. DDoS attack is a major information security threat and a means of cyber attacks. DDoS attacks are difficult to detect in advance and to defense effectively. To this end, a DMZ is set up in front of a network infrastructure and a particular server for defensive information security. Because There is the proliferation of mobile devices and apps, and the activation of android diversify DDoS attack methods. a DMZ is a limit to detect and to protect against DDoS attacks. This paper proposes an information security method to detect and Protect DDoS attacks from the terminal phase using a Preemptive military strategy concept. and then DDoS attack detection and protection app is implemented and proved its effectiveness by reducing web service request and memory usage. DDoS attack detection and protecting will ensure the efficiency of the mobile network resources. This method is necessary for a continuous usage of a wireless network environment for the national security and disaster control.

특성화 사설 네트워크 정보보호를 위한 접근권한 추론모드에 관한 연구 (A Study on Access Authorization Inference Modes for Information Security of Specialized Private Networks)

  • 서우석
    • 디지털산업정보학회논문지
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    • 제10권3호
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    • pp.99-106
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    • 2014
  • The most significant change and trend in the information security market in the year of 2014 is in relation to the issue and incidents of personal information security, which leads the area of information security to a new phase. With the year of 2011 as the turning point, the security technology advanced based on the policies and conditions that combine personal information and information security in the same category. Such technical changes in information security involve various types of information, rapidly changing security policies in response to emerging illegal techniques, and embracing consistent changes in the network configuration accordingly. This study presents the result of standardization and quantification of external access inference by utilizing the measurements to fathom the access authorization performance in advance for information security in specialized networks designed to carry out certain tasks for a group of clients in the easiest and most simple manner. The findings will provide the realistic data available with the access authorization inference modes to control illegal access to the edge of a client network.

Finite Element Modeling and Nonlinear Analysis for Seismic Assessment of Off-Diagonal Steel Braced RC Frame

  • Ramin, Keyvan;Fereidoonfar, Mitra
    • International Journal of Concrete Structures and Materials
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    • 제9권1호
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    • pp.89-118
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    • 2015
  • The geometric nonlinearity of off-diagonal bracing system (ODBS) could be a complementary system to covering and extending the nonlinearity of reinforced concrete material. Finite element modeling is performed for flexural frame, x-braced frame and the ODBS braced frame system at the initial phase. Then the different models are investigated along various analyses. According to the experimental results of flexural and x-braced frame, the verification is done. Analytical assessments are performed in according to three dimensional finite element modeling. Nonlinear static analysis is considered to obtain performance level and seismic behaviour, and then the response modification factors calculated from each model's pushover curve. In the next phase, the evaluation of cracks observed in the finite element models, especially for RC members of all three systems is performed. The finite element assessment is performed on engendered cracks in ODBS braced frame for various time steps. The nonlinear dynamic time history analysis accomplished in different stories models for three records of Elcentro, Naghan and Tabas earthquake accelerograms. Dynamic analysis is performed after scaling accelerogram on each type of flexural frame, x-braced frame and ODBS braced frame one by one. The base-point on RC frame is considered to investigate proportional displacement under each record. Hysteresis curves are assessed along continuing this study. The equivalent viscous damping for ODBS system is estimated in according to references. Results in each section show the ODBS system has an acceptable seismic behaviour and their conclusions have been converged when the ODBS system is utilized in reinforced concrete frame.

21세기 한방건강관련산업의 역할과 전망 (Functions and prospects of oriental health related industries in 21st century)

  • 김광중
    • 대한한의학회지
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    • 제19권1호
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    • pp.430-443
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    • 1998
  • The research on the actual condition of the oriental health related industry has been made with defining it's phase. As a result, I have come to develope korean-type health model, which can solve the problems derived from the past herb medicine industry. The prospects and roles of the oriental health related industries are as follows: The phase adjustment of the oriental health related industry. The problems of modern medical science happens in the beginning of 21st century, the importance of oriental health improvement in the field of health business is now being on the rise. therefore it is necessary to readjust the present status of the oriental medicine and to take it into health area. Should the responsible institutes regarded on oriental medicine make clear prescription in terms of oriental health industry's role and limitation, they could contribute health circumstance in the 21st century. This is because oriental health related industry can be utiliged in not only protective area and curable area. The present situation of the oriental health related industry. These herb medical societies are flooded with various oriental health industry apart from the legal systematic control so far health industry apart from the legal systematic control so far. The expected survey can not be complete but random under these situations. Nevertheless oriental medical health industry area such as a diet cure, exercise treatment and living condition cure are being considerably expanded, especially living facilities improvement and mind control areas are toward worldwide. Consquently herb health industries are now? consistantly developed by the influence of western nature treatment stemmed from the oriental medicine theory. The role and prospect of the oriental health related industry in 21st century. The oriental health industries can be helpful for the human being's health improvement in general but by the lack of scholastic oriental health theory, it does not contribute to the health welfare. If these problems are made up for in the field of theory area, the oriental health related industry will surely have the potentiallity and know how for health welfare. The successive role of these industry is depended on the fact that the characteristics of the oriental medicine should adjust to the real society with the systematic management. In the 21C, oriental health industry will certainly be vitalized owing to the social and periodical request especially in the area of oriental medical industry, oriental health drink industry, oriental health mind exercise industry, oriental health leasure industry and oriental health complex management industry. Among these areas, it is the oriental health complex amagement industry that will be the limestone of prosperity of the oriental health industry in 21C. Proposal for the social contribution of the oriental health related industry in the 21C. To achive the ultimate role of the oriental health industry in the 21c, first we should know how to use the oriental medicine. Second We should make an effort to revitalize the oriental health industry. So it is indespensible that government, academic institution and enterprise should concentrate their interest on the oriental health industry with common knowledge and systematic management in advance.

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3상 대용량 무선 전력 전송 시스템 (Three-phase high power wireless transmission system)

  • 오정식;이명진;차승태;김주용;이광운;박태식
    • 전기전자학회논문지
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    • 제21권3호
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    • pp.195-201
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    • 2017
  • 대용량 무선 전력 전송 시스템은 ESS, 배터리 장치 등의 발전을 위한 핵심 기술이다. 무선 전력 전송 장치는 현재 자기유도 및 자기공진 기술들이 주를 이루고 있으며 유선 전력 전송에 비해 전력 전송 용량이 낮고 효율이 낮은 단점이 있다. 이 논문에서는 자기 결합을 갖는 가변속 모터 시스템을 기반으로 하는 대용량 무선 전력 전송 시스템을 제안하고자 한다. 제안된 방식은 대용량 전력 전송이 가능하며, 고효율과 낮은 고장 가능성의 장점을 가지고 있으며 시뮬레이션과 실험을 통해 제안된 기법의 성능을 검증하였다.

Kinematical Analysis of Somersault with Twist in Men's Vault: Focusing on the Lou Yun and Akopian Motions

  • Lim, Kyu-Chan;Park, Hyung Suh
    • 한국운동역학회지
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    • 제26권3호
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    • pp.243-248
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    • 2016
  • Objective: The aim of this study was to determine the kinematical characteristics of somersault with twist in the Lou Yun and Akopian motions and to provide useful information to gymnastic athletes in men's vault. Method: The study subjects were 12 male adult top athletes. After 12 trials (7 Lou Yun and 5 Akopian trials) filmed by using two digital high-speed camcorders set at 90 frames/sec, kinematical data were collected through the direct linear transformation (DLT) method. The mean differences in biomechanical variables were compared during the second flight upward phase. The kinematic characteristics of somersault with twist in the Lou Yun and Akopian motions were identified. Results: In Lou Yun motion, the vertical release velocity through horse breaking was not difficult to obtain, so the athletes had enough time to prepare for the twist. Therefore, the Lou Yun motion has an advantage to make a cat twist in the pike posture. In the Akopian motion, obtaining the horizontal velocity through horse pushing was so easy that the Akopian athletes attained a large angular impulse and angular momentum. Therefore, the Akopian motion has an advantage to making a tilt twist in the body tilting posture. Conclusion: This study suggests that gymnastic athletes should control their body segment movements in order to increase the twisting angular velocity of the whole body, which requires regulation of the longitudinal moment of inertia of the body. Moreover, athletes should prepare for the shoulder and hip twists early in order to make the landing position in advance.

건설현장 소음제한을 고려한 최적 스케줄링 프로세스 모델 개발 (Developing an Optimized Scheduling Process Model for Controlling the Noise in Construction Field)

  • 이승학;손재호;이승현
    • 한국건축시공학회지
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    • 제14권5호
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    • pp.467-476
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    • 2014
  • 최근 건설공사의 기계화로 인한 많은 장비 투입으로 인하여 주변 주민들이 현장 소음에 인한 피해보상을 요구하는 민원이 증가하고 있다. 하지만 현장소음은 예방차원이 아닌 공사 진행과정에서만 제한적으로 관리되며 민원이 발생하고 나서야 대부분의 대처가 이루어지고 있는 실정이다. 또한, 이러한 민원을 해결하기 위해서는 비용과 시간이 과다하게 소요되는데 이는 건설사에 부정적인 영향을 미치게 된다. 이에 본 연구는 착공 전부터 계획된 공사기간과 장비투입 조건을 활용하여 최적 공사비를 찾는 알고리즘을 제안하고 최적 공정표를 도출할 수 있는 스케줄링 프로세스 모델을 개발하는 데 그 목적이 있다. 또한, 이를 활용하여 현장관리자가 공사계획 수립 시 소음발생 여부에 따라 민원이 발생할 때 예측되는 비용정보 및 소음제한에 따른 공사비와 공사기간의 변화 정도를 비교 분석함으로써 보다 합리적이고 효율적인 공사 관리를 수행할 수 있도록 한다.

SBAS SIGNAL SYNCHRONIZATION

  • Kim, Gang-Ho;Kim, Do-Yoon;Lee, Taik-Jin;Kee, Changdon
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.309-314
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    • 2006
  • In general DGPS system, the correction message is transferred to users by wireless modem. To cover wide area, many DGPS station should be needed. And DGPS users must have a wireless modem that is not necessary in standalone GPS. But SBAS users don't need a wireless modem to receive DGPS corrections because SBAS correction message is transmitted from the GEO satellite by L1 frequency band. SBAS signal is generated in the GUS(Geo Uplink Subsystem) and uplink to the GEO satellite. This uplink transmission process causes two problems that are not existed in GPS. The one is a time delay in the uplink signal. The other is an ionospheric problem on uplink signal, code delay and carrier phase advance. These two problems cause ranging error to user. Another critical ranging error factor is clock synchronization. SBAS reference clock must be synchronized with GPS clock for an accurate ranging service. The time delay can be removed by close loop control. We propose uplink ionospheric error correcting algorithm for C/A code and carrier. As a result, the ranging accuracy increased high. To synchronize SBAS reference clock with GPS clock, I reviewed synchronization algorithm. And I modified it because the algorithm didn't consider doppler that caused by satellites' dynamics. SBAS reference clock synchronized with GPS clock in high accuracy by modified algorithm. We think that this paper will contribute to basic research for constructing satellite based DGPS system.

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Ultrastructures of Oocyte Development and Electrophoretic Patterns of the Yolk Protein Following HCG Treatment in Korean Native Catfish (Silurus asotus)

  • Yoon, J.M.;Chung, E.Y.;Kim, G.W.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권2호
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    • pp.174-183
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    • 2001
  • During the rapid phase of gonadal development of the freshwater teleost, the catfish (Silurus asotus), the influence of hCG upon the inducement of final oocyte maturation and spawning was investigated electrophoretically and ultrastructurally. The electrophoretic patterns obtained were different in the presence and absence of some of the major or minor zones, because of the hormone level in catfish. The vitellogenin of hormone-treated fish was stained more intensively than that of sham-treated fish. These proteins showed some minor or main bands of egg extracts which migrated at positions corresponding to molecular weights of approximately 90,000. However, the thickness of electrophoretic band in molecular weight for hCG-treated fish was slightly lower than that for saline control. It seemed the plasma protein with molecular weight of approximately 45,000 in hCG-treated fish disappeared. In contrast to the control fish, the ovaries in the catfish treated with hCG shows a marked ultrastructural change under the electron microscope. No dilated profiles were seen in the granulosa cells of the mature oocyte before ovulation. After germinal vesicle breakdown (GVBD), the zona radiata interna (ZRI) becomes more compact, and there is a loss of all the processes from the pore canals. There is a wide space between the vitelline membrane and zona radiata. Also, during final maturation, the microvillar processes from the oocyte are seen no longer to penetrate deeply into the extracellular spaces of the overlying granulosa cells, and the reticulate patterns of the zona radiata interna becomes occluded, giving the zona radiata a more solid appearance. It has been possible to initiate 100% oocyte maturation in yolk granules and follicles in vivo by treatment with hCG and a high water temperature ($27^{\circ}C$). In hCG-treated fish, the percentages of successful artificial fertilization and hatching were maximal at 15 h after a single injection. It seems clear that a long acting preparation containing hCG can be successfully used in prespawning fish to advance the final events of gonadal maturation and initiate spawning. Further studies are necessary to evaluate the potential of hCG to either stimulate or inhibit the reproductive development of fish at other stages of the seasonal reproductive cycle.

경험의 종류를 달리한 비계설정의 효과 분석 (The Effect of Scaffolding Composed of Different Kinds of Experience)

  • 이순주
    • 영재교육연구
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    • 제17권1호
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    • pp.51-76
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    • 2007
  • 본 연구에서는 경험의 종류를 달리하여 설정된 비계가 아동의 창의성 신장에 어떠한 영향을 미치는지를 알아보기 위하여 다음과 같이 연구대상을 선정하였다. 즉 경기도 소재 J초등학교 1학년 아동 156명과 6학년 134명을 대상으로 연구자는 상황적 경험과 이야기 경험으로 구성된 비계를 실험집단 아동에게 제공하였다. 창의성 검사 도구로는 Torrance의 창의적 사고력 검사지 중 그림 완성문제를 선택하여 사용하였다. 사전 사후검사를 실시한 후 비계설정을 통한 창의성 변화 양상을 비교 분석한 결과는 다음과 같다. 첫째, 사후검사에서 상황적 경험을 이용해 비계가 제시된 실험집단 아동들은 비계설정 후에 오히려 창의성이 감소되는 양상을 나타내보였으며 특히 창의성 하위요소 중 제목의 추상성과 정교성이 통계적으로도 의의 있는 감소 현상을 보여주었다. 반면, 이야기 경험을 이용해 비계가 제시된 실험집단의 경우에는 비계설정후에 매우 의미 있는 창의성 신장 양상을 나타내 보임으로써 상황적 경험을 제공받은 실험집단과 반대되는 모습을 보여주었다. 둘째, 설정된 비계로 인한 학년별 창의성 신장 양상이 어떠한지 알아본 결과, 1학년과 6학년 모두 이야기 경험을 이용해 비계를 설정한 경우, 이들의 창의성이 향상되는 반면, 상황적 경험을 제공하였을 때는 창의성이 감소되는 것으로 나타났다. 이러한 결과를 통해 계획적 조직적으로 설정되는 모든 비계들이 아동의 능력 향상에 긍정적인 영향만을 미치는 것이 아니라 비계의 종류와 특성에 따라 긍정적인 영향뿐만 아니라 때로는 부정적인 영향도 미칠 수 있다는 것을 알 수 있었다. 또한 이러한 연구 결과는 비계설정이라는 교수 학습방안을 적용할 때는 아동의 연령과 흥미를 고려하여 어떠한 종류의 매개체를 이용한 비계설정이 이들의 능력 향상에 긍정적인 영향을 미치는지를 먼저 밝혀낸 후, 구체적인 교수 학습 활동에 적용할 필요가 있음을 시사해 준다.