• Title/Summary/Keyword: Storage-function method

Search Result 320, Processing Time 0.034 seconds

A Study on Parameters Estimation of Storage Function Model Using the Genetic Algorithms (유전자 알고리듬을 이용한 저류함수모형의 매개변수 추정에 관한 연구)

  • Park, Bong-Jin;Cha, Hyeong-Seon;Kim, Ju-Hwan
    • Journal of Korea Water Resources Association
    • /
    • v.30 no.4
    • /
    • pp.347-355
    • /
    • 1997
  • In this study, the applicability of genetic algorithms into the parameter estimation of storage function method for flood routing model is investigated. Genetic algorithm is mathematically established theory based on the process of Darwinian natural selection and survival of fittest. It can be represented as a kind of search algorithms for optima point in solution space and make a reach on optimal solutions through performance improvement of assumed model by applying the natural selection of life as mechanical learning province. Flood events recorded in the Daechung dam are selected and used for the parameter estimation and verification of the proposed parameter estimation method by the split sample method. The results are analyzed that the performance of the model are improved including peak discharge and time to peak and shown that the parameter Rsa, and f1 are most sensitive to storage function model. Based on the analysis for estimated parameters and the comparison with the results from experimental equations, the applicability of genetic algorithm is verified and the improvements of those equations will be used for the augmentation of flood control efficiency.

  • PDF

A Study on Creation of Secure Storage Area and Access Control to Protect Data from Unspecified Threats (불특정 위협으로부터 데이터를 보호하기 위한 보안 저장 영역의 생성 및 접근 제어에 관한 연구)

  • Kim, Seungyong;Hwang, Incheol;Kim, Dongsik
    • Journal of the Society of Disaster Information
    • /
    • v.17 no.4
    • /
    • pp.897-903
    • /
    • 2021
  • Purpose: Recently, ransomware damage that encrypts victim's data through hacking and demands money in exchange for releasing it is increasing domestically and internationally. Accordingly, research and development on various response technologies and solutions are in progress. Method: A secure storage area and a general storage area were created in the same virtual environment, and the sample data was saved by registering the access process. In order to check whether the stored sample data is infringed, the ransomware sample was executed and the hash function of the sample data was checked to see if it was infringed. The access control performance checked whether the sample data was accessed through the same name and storage location as the registered access process. Result: As a result of the experiment, the sample data in the secure storage area maintained data integrity from ransomware and unauthorized processes. Conclusion: Through this study, the creation of a secure storage area and the whitelist-based access control method are evaluated as suitable as a method to protect important data, and it is possible to provide a more secure computing environment through future technology scalability and convergence with existing solutions.

Head Slider Design Using Approximation Method For Load/Unload Applications (근사화 기법을 이용한 Load/Unload 용 헤드 슬라이더 최적설계)

  • Son, Seok-Ho;Yoon, Sang-Joon;Park, No-Cheol;Park, Young-Pil;Choi, Dong-Hoon
    • Transactions of the Society of Information Storage Systems
    • /
    • v.2 no.3
    • /
    • pp.169-177
    • /
    • 2006
  • In this study, we present the optimization of a head slider using kriging method in order to reduce lift-off force during unloading process with satisfying reliable flying attitude in steady state. To perform an optimization process efficiently, a simplified lift-off force model, which is a function of air bearing suction force and flying attitudes, is created by kriging method. The EMDIOS, which is the process integration and design optimization software developed by iDOT, is used to automatically wrap the analysis with the optimization and efficiently implements the repetitive works between analyzer and optimizer. An optimization problem is formulated to reduce the lift-off force during unloading process while satisfying the flying attitude in reliable range over the entire recording band and reducing the probability of contact between slider and disk. The simulation result shows that the amplitude of lift-off force of optimized L/UL slider is reduced about 62%, compared with that of initial slider model. It is demonstrated by the dynamics L/UL simulation that the optimum slider incorporated with the suspension is not only smoothly loaded onto disk but also properly unloaded onto the ramp.

  • PDF

Measurement of the Slider-Disk Contact during Load/Unload process with AE and Electrical Resistance (Load/Unload 시 AE 와 전기저항을 이용한 슬라이더-디스크 충돌측정에 관한 연구)

  • Kim, Seok-Hwan;Lee, Yong-Hyun;Lim, Soo-Cheol;Park, Kyoung-Su;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
    • /
    • v.3 no.4
    • /
    • pp.160-166
    • /
    • 2007
  • In this paper, the measured electrical resistance method is proposed to analyze the ramp-tab contact during the load/unload (L/UL) process. Since this method supplies the voltage change due to the resistance change, we can easily and conveniently identify the ramp-tab contact from the acoustic emission (AE) signal. At first, we carefully deposit the conductive material on the surface of the conventional ramp by sputtering method. The ratio frequency (RF) magnetron co-sputtering system is applied to accomplish the deposited double-layers on the ramp surface. One layer is the stainless steel for the conductive layer and the other is the titanium layer for the cohesive function between the ramp surface and the stainless steel layer. In order to guarantee the stiffness and damping properties of the original ramp, the deposited conductive layer is intended to have very thin thickness. After integration the proposed ramp device into the L/UL system and networking the electrical resistance circuit, the L/UL performance is experimentally evaluated by comparing the measured electrical resistance signal and AE signal.

  • PDF

A Study on the Construction of Status Display Equipment for Soft-RAID System of Linux Server using Hardware (하드웨어에 의한 리눅스 서버 소프트-RAID 시스템의 상태표시 장치 구성에 관한 연구)

  • Na, Won-Shik;Lee, Hyun-Chang
    • Journal of Software Assessment and Valuation
    • /
    • v.15 no.2
    • /
    • pp.95-100
    • /
    • 2019
  • In this paper, we propose a simple hardware reporting method for errors in soft-RAID systems of Linux OS. Compared with other reporting methods, the proposed method displays error status intuitively without any additional access process such as log-in process or home-page access. In particular, the server actively displays the error status, so the administrator can take immediate action. In order to confirm the effectiveness of the proposed method, the experimental circuit was constructed and the experimental results showed that the error was actively displayed when an error occurred in the storage device. As such, a soft-RAID system can perform almost the same function as a hardware RAID system, thereby ensuring server data reliability at low cost.

Learning Reference Vectors by the Nearest Neighbor Network (최근점 이웃망에의한 참조벡터 학습)

  • Kim Baek Sep
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • v.31B no.7
    • /
    • pp.170-178
    • /
    • 1994
  • The nearest neighbor classification rule is widely used because it is not only simple but the error rate is asymptotically less than twice Bayes theoretical minimum error. But the method basically use the whole training patterns as the reference vectors. so that both storage and classification time increase as the number of training patterns increases. LVQ(Learning Vector Quantization) resolved this problem by training the reference vectors instead of just storing the whole training patterns. But it is a heuristic algorithm which has no theoretic background there is no terminating condition and it requires a lot of iterations to get to meaningful result. This paper is to propose a new training method of the reference vectors. which minimize the given error function. The nearest neighbor network,the network version of the nearest neighbor classification rule is proposed. The network is funtionally identical to the nearest neighbor classification rule is proposed. The network is funtionally identical to the nearest neighbor classification rule and the reference vectors are represented by the weights between the nodes. The network is trained to minimize the error function with respect to the weights by the steepest descent method. The learning algorithm is derived and it is shown that the proposed method can adjust more reference vectors than LVQ in each iteration. Experiment showed that the proposed method requires less iterations and the error rate is smaller than that of LVQ2.

  • PDF

Efficient Verifiable Top-k Queries in Two-tiered Wireless Sensor Networks

  • Dai, Hua;Yang, Geng;Huang, Haiping;Xiao, Fu
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.9 no.6
    • /
    • pp.2111-2131
    • /
    • 2015
  • Tiered wireless sensor network is a network model of flexibility and robustness, which consists of the traditional resource-limited sensor nodes and the resource-abundant storage nodes. In such architecture, collected data from the sensor nodes are periodically submitted to the nearby storage nodes for archive purpose. When a query is requested, storage nodes also process the query and return qualified data as the result to the base station. The role of the storage nodes leads to an attack prone situation and leaves them more vulnerable in a hostile environment. If any of them is compromised, fake data may be injected into and/or qualified data may be discarded. And the base station would receive incorrect answers incurring malfunction to applications. In this paper, an efficient verifiable top-k query processing scheme called EVTQ is proposed, which is capable of verifying the authentication and completeness of the results. Collected data items with the embedded information of ordering and adjacent relationship through a hashed message authentication coding function, which serves as a validation code, are submitted from the sensor nodes to the storage nodes. Any injected or incomplete data in the returned result from a corresponded storage node is detected by the validation code at the base station. For saving communication cost, two optimized solutions that fuse and compress validation codes are presented. Experiments on communication cost show the proposed method is more efficiency than previous works.

The Analysis of Inground LNG Storage Tank Compression Ring Behavior during Concrete Pouring (콘크리트 타설에 따른 지하식 LNG 저장탱크 컴프레션 링 거동 분석)

  • Kim Y.K.;Kim J.H.;Yoon I.S.;Oh B.T.;Yang Y.M.
    • 한국가스학회:학술대회논문집
    • /
    • 2004.11a
    • /
    • pp.82-87
    • /
    • 2004
  • Compression ring is a part of LNG storage tank. The main function of the compression ring is connected the roof plate with concrete side wall. End of its one side is embedded in the side concrete wall and the other's connected with the roof plate by welding. It is designed to support stably for all the loads such as self weight of steel roof, inner pressure and concrete weight. We fulfill the FEM analysis to analysis the compression ring behavior during construction. Also we studied the effect of the change of design variables. On the basis of the results, we could introduce a more reasonable design method for compression ring.

  • PDF

Experimental realization of an imaging system using wavefront coding in mobile phone camera (휴대폰용 카메라 모듈에서 파면코딩을 통한 이미지 시스템 실험구현)

  • Kim, Jong-Pil;Lee, Sang-Hyuck;Park, No-Cheol;Park, Young-Pil;Park, Kyoung-Su
    • Transactions of the Society of Information Storage Systems
    • /
    • v.5 no.1
    • /
    • pp.36-40
    • /
    • 2009
  • We describe the experimental realization of image system using wavefront coding in 3-Mega pixel mobile phone camera. We designed aspheric lens to extend the depth of field (DOF) using wavefront coding. In addition, through the aspheric lens and lens barrel manufacturing, we obtained a raw image from a camera module. In our method, the acquired images are restored in the spatial frequency domain using the proposed filter and the spatial frequency response (SFR) is calculated. The proposed filters are composed of image denoising filter using low band pass filter in frequency domain and restoration filter for image restoration. Finally, we achieve an enhanced image by super-resolution image processing. Visual examples are given to demonstrate the performance of the proposed filter.

  • PDF

On the Untact ICT based New Concept Storage Device Design by Interworking SysML and CAD Data to Improve the Development Efficiency

  • Kim, Myung Sung;Park, Jae Min;Kim, Young Min
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.14 no.3
    • /
    • pp.258-269
    • /
    • 2022
  • In these days, innovative functions are required to unmanned parcel delivery lockers. As non-face-to-face transactions become the center due to the recent COVID-19 pandemic, many problem occurs in society such as theft crimes and lack of loading space. Therefore, New concept storage device is developed in korea. It has the functions that minimizes empty spaces by using the internal transport device to enable efficient space loading and refrigerate goods such as foods. In order to systematically approach the system design of the unmanned parcel delivery lockers which is the new function is applied, We applied model-based system engineering to improve the development efficiency and use a system modeling language to express the system. We conducted interworking research of CAD data including system modeling and design data. it is expected that this method will increase the effective development efficiency such as maintenance traceability and reduction of development period and cost.