• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권8호
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• pp.2140-2156
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• 2023

The Wireless Sensor Network (WSN), is constructed out of teeny-tiny sensor nodes that are very low-cost, have a low impact on the environment in terms of the amount of power they consume, and are able to successfully transmit data to the base station. The primary challenges that are presented by WSN are those that are posed by the distance between nodes, the amount of energy that is consumed, and the delay in time. The sensor node's source of power supply is a battery, and this particular battery is not capable of being recharged. In this scenario, the amount of energy that is consumed rises in direct proportion to the distance that separates the nodes. Here, we present a Hybrid Firefly Glow-Worm Swarm Optimization (HF-GSO) guided routing strategy for preserving WSNs' low power footprint. An efficient fitness function based on firefly optimization is used to select the Cluster Head (CH) in this procedure. It aids in minimising power consumption and the occurrence of dead sensor nodes. After a cluster head (CH) has been chosen, the Glow-Worm Swarm Optimization (GSO) algorithm is used to figure out the best path for sending data to the sink node. Power consumption, throughput, packet delivery ratio, and network lifetime are just some of the metrics measured and compared between the proposed method and methods that are conceptually similar to those already in use. Simulation results showed that the proposed method significantly reduced energy consumption compared to the state-of-the-art methods, while simultaneously increasing the number of functioning sensor nodes by 2.4%. Proposed method produces superior outcomes compared to alternative optimization-based methods.

• 한국시뮬레이션학회논문지
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• 제13권3호
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• pp.21-29
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• 2004

The major objective of this paper is to analyze network vulnerabilities using the SIMVA (SIMualtion-based Vulnerability Analyzer). SIMVA is capable of monitor network status and analyze vulnerabilities automatically. To do this, we have employed the advanced modeling and simulation concepts such as SES/MB (System Entity Structure / Model Base) framework, DEVS (Discrete Event System Specification) formalism, and experimental frame for developing network security models and simulation-based analysis of vulnerability. SIMVA can analyze static vulnerability as well as dynamic vulnerability consistently and quantitatively. In this paper, we verified and tested the capability of application of SIMVA by slammer worm attack scenario.

• 전자공학회논문지S
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• 제35S권12호
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• pp.109-120
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• 1998

본 논문에서는 퍼지 벌레 검색과 최소-최대 군집화 알고리즘에 기반한 영상 영역화 기법을 제안한다. 전체 영상에서 에지 정보는 픽셀들의 공간 관계를 포함하게 되며, 이를 위해 목적 함수들의 인자를 조정하여 퍼지 벌레의 행동을 정의하며, 에지 정보를 검사하는 방법으로 퍼지 벌레값과 최소-최대 노드를 이용한다. 에지 추출을 사용하는 현재의 영역화 방법들은 수학적 모델에 기반한 매스크 정보를 필요로 하며, 매스크 연산으로 인하여 수행 시간도 많이 걸리게 된다. 반면에, 제안하는 알고리즘은 퍼지 벌레의 검색에 따라 단일 연산을 수행하게 된다. 제안하는 알고리즘에서 필요한 범위의 크기를 스스로 결정하고 빠르고 강력한 계산을 수행하기 위해 최적해를 찾는 유전 알고리즘을 도입하고자 한다. 추가적으로, 영상의 그레이-히스토그램에서 퍼지 검색과 군집화를 수행하기 위해 유전 알고리즘을 사용하는 유전 퍼지 벌레 검색과 유전 최소-최대 군집화가 제안된다. 시뮬레이션 결과는 제안된 알고리즘이 히스토그램을 사용하여 적응적으로 양자화되며, 계산 시간과 메모리를 적게 요구하는 단일 검색 방법을 수행한다는 것을 보여준다.

• 한국멀티미디어학회논문지
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• 제8권10호
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• pp.1360-1368
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• 2005

플라즈마 디스플레이 패널에서는 표현 가능한 회색 준위의 수를 향상시키기 위해 오차 확산 방법이 주로 사용되고 있다. 이 방법은 표현 가능한 회색 준위 수의 증가를 가져오나 오차 확산 과정에서 발생하는 웜라이크 패턴은 오차 확산 처리 이후의 여러 가지 영상 처리 과정을 거치면서 증가되어 화질저하의 요인이 된다. 본 논문에서는 플라즈마 디스플레이 패널의 화질저하를 일으키는 웜라이크 패턴의 증가를 막기 위하여 average picture level 특성을 고려한 화질개선 방법을 제안하였다. 제안한 방법으로 모의실험을 한 결과, 플라즈마 디스플레이 패널의 표현 가능한 회색 준위의 수가 증가되었고, 웜라이크 패턴은 현저히 감소하였으며, 각 회색 준위의 상관 색온도 특성이 균일하게 됨을 확인하였다.

• 한국정보처리학회논문지
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• 제6권4호
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• pp.1090-1097
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• 1999

열악한 환경엣 동작되는 멀티컴퓨터는 요소결함(component faults)이 존재하는 상황에서도 정상적 동작을 보장할 수 있도록 설계되어야 한다. 이를 위한 하나의 방법으로 결함포용 라우팅(fault-tolerant routing) 기법이 고려될 수 있다. 본 논문에서는 n-차원 메쉬 네트워크를 기본 토폴로지로 선택하여 이러한 네트워크의 임의의 장소에서 링크결함이 발생했을 경우에도 메시지들을 목적지로 전달시킬 수 있는 결함포용 라우팅 알고리즘을 제안한다. 제안된 결함포용 라우팅 알고리즘은 기본적으로 WH(WormHole)라우팅 방식을 채택하며, deadlock-free를 실현하기 위하여 한 개의 물리적 채널을 공유하는 복수 개의 가상채널들(virtual channels)을 사용한다. 결론적으로 컴퓨터 시뮬레이션을 통해 제안된 알고리즘이 널리 알려진 X-Y 라우팅 알고리즘보다 향상된 성능을 갖는다는 사실을 입증한다.

• 정보보호학회논문지
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• 제17권1호
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• pp.57-66
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• 2007

스캐닝 웜은 네트워크 관리자가 미처 대응하기 전에 넓게 전파되므로 차단하기 힘들고 그 피해가 상당히 크다. 따라서 자동으로 스캐닝 웜의 발생을 탐지하고 이에 대응할 수 있는 방법이 필요하다. 본 논문에서는 스캐닝 웜의 트래픽 특성을 분석하여 정상 트래픽과 이상 트래픽을 구분할 수 있는 탐지 알고리즘을 제안한다. 스캐닝 웜의 탐지를 위해 variance, VMR 및 correlation coefficient를 이용하는 방법을 제안하고, 시뮬레이션을 통해 기존의 방법과 성능을 비교하였다. 그 결과 기존의 방법에 비하여 간단한 계산을 통해 스캐닝 웜의 효율적인 탐지가 가능함을 확인하였다.

• 한국CDE학회논문집
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• 제1권2호
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• pp.150-157
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• 1996

The hob is considered as an effective gear cutting tool for achieving the various gears such as spur gear, helical gear, worm gear and so on. To enhance the productivity and precision of hobs and the competitive ability of domestic CNC hob relieving lathes, a CAM system for CNC hob relieving lathe needs to be realized. In this study, the CAM system is developed based on the personal computer and C language. Besides the automatic generation of CNC data, the developed CAM system has the various capabilities related to the generation of tool path, the cutting simulation for verifying the generated CNC data and forecasting the cutting time, the DNC operation for communicating the CNC data with CNC controller by RS232C port, and the estimation of undercut length for verifying the hob cutting conditions.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 춘계학술대회논문집
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• pp.7-15
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• 1996

A Manufacturing process of the power steering worm blank is analyzed by FEM aimulation. The process includes mainly three operations such as indentation, extrusion, and upsetting, which was designed bya forming equipment expert. The results of simulation are summarized in terms of load-stroke relationships, die pressure distributions, effective strain distribution, and deforming patterns for each forming operation. Also, Efforts are focused to get the reason that the tool expert designed the forming process in three operations. The results of the simulation are to be useful for the next advanced process planning in terms of good dimesional accuracy, savings in material and machining, no deforaming defects and imporvements in mechanical properties.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권5호
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• pp.2186-2203
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• 2020

Security administrators of companies and organizations need to come up with proper countermeasures against cyber-attacks considering infrastructures and security policies in their possession. In order to develop and verify such countermeasures, the administrators should be able to reenact both cyber-attacks and defenses. Simulations can be useful for the reenactment by overcoming its limitations including high risk and cost. If the administrators are able to design various scenarios of cyber-attacks and to develop simulation models from their viewpoints, they can simulate desired situations and observe the results more easily. It is challenging to simulate cyber-security issues, because there is lack of theoretical basis for modeling a wide range of the security field as well as pre-defined basic components used to model cyber-attacks. In this paper, we propose a modeling method for cyber-security simulations by developing a basic component and a composite model, called Abstracted Cyber-Security Unit Model (ACSUM) and Abstracted Cyber-security SIMulation model (ACSIM), respectively. The proposed models are based on DEVS(Discrete Event systems Specification) formalism, a modeling theory for discrete event simulations. We develop attack scenarios by sequencing attack behaviors using ACSUMs and then model ACSIMs by combining and abstracting the ACSUMs from a security perspective. The concepts of ACSUM and ACSIM enable the security administrators to simulate numerous cyber-security issues from their viewpoints. As a case study, we model a worm scenario using ACSUM and simulate three types of simulation models based on ACSIM from a different security perspective.

• 한국산업융합학회 논문집
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• 제24권5호
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• pp.597-608
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• 2021

The control head components used in small military vessels are designed to be domestically produced, prototypes, structural analysis, and casting methods are designed and cast. The control head assembly consists of a lever, an aluminum outside cover, Middle, front gear cover, back gear cover, and a zinc worm gear. In order to reverse the design of each component, 3D scanning device was used, 3D modeling was performed by CATIA, and prototype productions were carried out by 3D printer. In order to reduce the cost of components, gating system is used by gravity casting method. The SRG ratio of 1:0.9:0.6 was set by applying non-pressurized gating system to aluminum parts, 1:2.2:2.0 and pressurized gating system to zinc parts, and the shapes of sprue, runner and gate were designed. The results of porosity were also confirmed by casting analysis in order to determine whether the appropriate gating system can be designed. The results showed that all parts started solidification after filling completely. ANSYS was used for structural analysis, and the results confirmed that all five components had a safety factor of 15 more. All castings are free of defects in appearance, and CT results show only very small porosity. ZnDC1 zinc alloy worm gear has a tensile strength of 285 MPa and an elongation of 8%. The tensile strength of the four components of A356 aluminum alloy is about 137-162 MPa and the elongation is 4.8-6.5%.