• Title, Summary, Keyword: Modification

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Study on the Response Modification Factor for a Lightweight Steel Panel-Modular Structure Designed as a Dual Frame System (이중골조시스템으로 설계된 복강판-모듈러 구조물의 반응수정계수에 관한 연구)

  • Lee, Eo-Jin;Hong, Sung-Gul
    • Journal of the Earthquake Engineering Society of Korea
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    • v.15 no.1
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    • pp.39-48
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    • 2011
  • In this present study, a response modification factor for a lightweight steel panel-modular system which is not clarified in a current building code was proposed. As a component of the response modification factor, an over-strength factor and a ductility factor were drawn from the nonlinear static analysis curves of the systems modeled on the basis of the performance tests. The final response modification factor was then computed by modifying the previous response modification factor with a MDOF (Multi-Degree-Of-Freedom) base shear modification factor considering the MDOF dynamic behaviors. As a result of computation for the structures designed as a dual frame system, ranging from 2-story to 5-story, the value of 4 was estimated as a final response modification factor for a seismic design, considering the value of 5 as an upper limit of the number of stories.

Password-based Authenticated Key Agreement Protocol Secure Against Advanced Modification Attack (Advanced Modification 공격에 안전한 패스워드 기반 키 동의 프로토콜)

  • Kwak, Jin;Oh, Soo-Hyun;Yang, Hyung-Kyu;Won, Dong-Ho
    • The KIPS Transactions:PartC
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    • v.11C no.3
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    • pp.277-286
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    • 2004
  • Password-based mechanism is widely used methods for user authentication. Password-based mechanisms are using memorable passwords(weak ferrets), therefore Password-based mechanism are vulnerable to the password guessing attack. To overcome this problem, man password-based authenticated key exchange protocols have been proposed to resist password guessing attacks. Recently, Seo-Sweeny proposed password-based Simple Authenticated Key Agreement(SAKA) protocol. In this paper, first, we will examine the SAKA and authenticated key agreement protocols, and then we will show that the proposed simple authenticated key agreement protocols are still insecure against Advanced Modification Attack. And we propose a password-based Simple Authenticated Key Agreement Protocol secure against Advanced Modification Attack.

The study on the military utilization of weather modification techniques and inducing their research priority (기상조절기술의 군사적 활용방안과 연구 우선순위 도출에 관한 연구)

  • Han, Seung Jo;Shin, Jin
    • Convergence Security Journal
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    • v.18 no.2
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    • pp.77-88
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    • 2018
  • The purposes of this paper are to research the military utilization of weather modification techniques and to induce their research priority when considering the Korean Peninsular environment and technical level. To achieve these goals, the advantages and disadvantages of weather modification technologies have been discussed, and the evaluation index evaluation was derived through the Delphi method, and the weight of the evaluation index and the final research priority were induced through analytic hierarchical process. Analysis shows that the ionospheric modulation technology has the highest priority in terms of effectiveness as a weapon system and compatibility in the Korean Peninsula environment. It is expected that Korean ionosphere modification can disturb C4ISR function of the enemy and guarantee ours reliably when operating PGM, military satellite, surveillance & reconnaissance equipments, etc. Other weather modification technologies except for ionosphere modification should be developed gradually in that potential threat can be expanded to neighboring countries after the Unification of the Korea.

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Nonlinear Dynamic Characteristics of Gear Driving System with Tooth Modification (치형수정된 기어구동계의 비선형 동특성 해석)

  • Cho, Yun-Su;Choi, Yeon-Sun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.25-30
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    • 2002
  • To reduce the vibration of a gear driving system, the modification of gear tooth from the orignal involute gear profile is usually done in gear manufacturers. The quantity of tooth modification has been decided on the basis of the interference between two gear teeth during gear meshing and the elastic deformation due to loading. However, the dynamic characteristics with tooth modification has to be investigated to avoid the instability to the variation of gear meshing stiffness and the nonlinearity due to gear backlash which results in sub- or super-harmonics in its responses. This research shows the dynamic characteristics with various tooth modifications in its type and quantity.

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Structural Dynamics Modification Using Position of Beam Stiffener on Plate (평판에서 빔 보강재의 결합 위치를 이용한 구조물 변경법)

  • Jung, Eui-Il;Park, Youn-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.599-604
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    • 2002
  • Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate.

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Study on the Optimum Modification and Modal Analysis of Stiffened Plate of Ship Hull Structure (신체의 Stiffened Plate 구조물의 모우드해석과 최적변경법에 관한 연구)

  • 박성현;박석주;고재용
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.51-58
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    • 2000
  • The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization ,finite element method (FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristic by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

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A Development of Tooth Profile Modification for Spur Gear (스퍼기어의 치형수정 프로그램의 개발)

  • Hwang, Jin-Young;Hwang, Sung-Wook;Kim, Tae-Wan;Cho, Yong-Joo
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.259-266
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    • 2002
  • The basic concept of 'tooth profile modification' is to change a part of the involute profile to reduce the load in that area and appropriate profile modifications can help gears to run quietly and resist scoring, pitting and tooth breakage. In this study, the modification of tooth profile to make a smooth transmission of the normal loads in spur gears has been developed. The modified tooth profile has been determined by the total deflection at contact points. We use the AGMA Standard to design basic gear profile, We also developed a gear design Program using tooth profile modification

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Pitch Modification based on a Voice Source Model (음원 모델에 기초한 합성음의 피치 조절)

  • Choi, Yong-Jin;Yeo, Su-Jin;Kim, Jin-Young;Sung, Koeng-Mo
    • Speech Sciences
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    • v.3
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    • pp.132-147
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    • 1998
  • Previously developed methods for pitch modification have not been based on the voice source model. Therefore, the synthesized speech often sounds unnatural although it may be highly intelligible. The purpose of this paper is to analyze the alteration of a voice source signal with pitch period and to establish the pitch-modification rule based on the result of this analysis. We examine the alteration of the interval of closing phase, closed phase and open phase using the excitation waveform as the pitch increases. In comparison to the previous methods which performed directly on the speech signal, the pitch modification method based on a voice source model shows high intelligibility and naturalness. This study might benefit the application to the speaker identification and the voice color conversion. Therefore the proposed method will provide high quality synthetic speech.

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Modeling for Measurement of Class Reusability in Object-Oriented Programs (객체 지향 프로그램에서 클래스 재사용성 측정 모델링)

  • Yun, Hui-Hwan;Gu, Yeon-Seol
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.3
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    • pp.580-588
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    • 1999
  • The reuse of software components from existing software system enhances productivity and reliability, decreases the cost of production in software development. The extraction of software components with high reusability from existing software system is very important in software reuse. The reuse of a class is classified into white-box reuse to reuse with modification and black-box reuse to reuse without modification. A class has the property of procedural language and object-oriented language. Therefore, it must measure reusability in consideration of two properties. In black-box reuse, independence of class is important quality. It can quantify through information hiding, coupling between objects, cohesion, etc. In white-box reuse, modification is the best important quality. It can quality through class complexity, coupling, cohesion, documentation, etc. We propose a new model for measurement of class reusability and the measure criteria in object-oriented program. A class that is measured by proposed model can judge whether the reuse with modification has the advantage or the reuse without modification has the advantage.

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Surface modification of Aluminum for mold by nitrogen ion implantation (질소이온주입에 의한 금형용 알루미늄의 표면개질특성)

  • 강혁진;안성훈;김경동;이재상;이재형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.254-259
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    • 2004
  • The research on surface modification technology has been advanced to change the properties of engineering material. Ion implantation is a novel surface modification technology to enhance the mechanical, chemical and electronic properties of mechanical parts. In this research, nitrogen ions are implanted into aluminum for mold to improve endurance and life span. To analyze modification of surface properties, micro hardness, friction coefficient, wear resistance, contact angle, and surface roughness were measured. Hardness of ion implanted specimens was higher than untreated specimen and friction coefficient was also improved. In this experiment, it can be expected that nitrogen ion implantation can contribute to enhance the mechanical properties of material and ion implantation technology may also be applied to other materials.

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