• Title/Summary/Keyword: Program Codes

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A Study on the Service Life Prediction of Reinforced Concrete Structures with Chloride Penetration (철근콘크리트 구조물의 염해에 의한 사용수명 예측에 관한 연구)

  • Kim Dong-Baek;Kwon Ki-Jun;Park Byung-Wook
    • Journal of the Korean Society of Safety
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    • v.20 no.2 s.70
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    • pp.113-118
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    • 2005
  • Recently, the corrosion of reinforced concrete structures has received great attention related with the deterioration of sea-side structures, such as new airport, bridges, and nuclear power plants. In this regards, many studies have been done on the chloride attack in concrete structures. The purpose of the present study is to explore the influences of chloride attack parameters to service life of reinforced concrete structures and to propose the rational program for the guarantee of service life. for this purpose, several codes for durability design have been examined and the diffusion analysis based on Fick's second law has been performed with various parameter value. The present study indicates that durability design code of Japan Society of Civil Engineers is more rational than other codes but the application of durability design code of JSCE to domestic durability design needs more studies to the various parameter values related with chloride penetration.

Development of Viscoelastic Finite Element Analysis Code for Pavement Structures (도로포장 구조해석을 위한 점탄성 유한요소 해석코드 개발)

  • Lee, Chang-Joon;Yoo, Pyeong-Jun;Choi, Ji-Young;Ohm, Byung-Sik
    • International Journal of Highway Engineering
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    • v.14 no.5
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    • pp.1-9
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    • 2012
  • PURPOSES: A viscoelastic axisymmetric finite element analysis code has been developed for stress analysis of asphalt pavement structures. METHODS: Generalized Maxwell Model (GMM) and 4-node isoparametric element were employed for finite element formulation. The code was developed using $C^{+}^{+}$ computer program language and named as KICTPAVE. For the verification of the developed code, a structural model of a pavement system was constructed. The structural model was composed of three layers: asphalt layer, crushed stone layer, and soil subgrade. Two types of analysis were considered for the verification: (1)elastic static analysis, (2)viscoelastic time-dependent analysis. For the elastic static analysis, linear elastic material model was assigned to all the layers, and a static load was applied to the structural model. For the viscoelastic time-dependent analysis, GMM and linear elastic material model were assigned to the asphalt layer and all the other layers respectively, and a cyclic loading condition was applied to the structural model. RESULTS: The stresses and deformations from KICTPAVE were compared with those from ABAQUS. The analysis results obtained from the two codes showed good agreement in time-dependent response of the element under the loading area as well as the surface deformation of asphalt layer, and horizontal and vertical stresses along the axisymmetric axis. CONCLUSIONS: The validity of KICTPAVE was confirmed by showing the agreement of the analysis results from the two codes.

A SUMMARY OF 50th OECD/NEA/CSNI INTERNATIONAL STANDARD PROBLEM EXERCISE (ISP-50)

  • Choi, Ki-Yong;Baek, Won-Pil;Kang, Kyoung-Ho;Park, Hyun-Sik;Cho, Seok;Kim, Yeon-Sik
    • Nuclear Engineering and Technology
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    • v.44 no.6
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    • pp.561-586
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    • 2012
  • This paper describes a summary of final prediction results by system-scale safety analysis codes during the OECD/NEA/CSNI ISP-50 exercise, targeting a 50% Direct Vessel Injection (DVI) line break integral effect test performed with the Advanced Thermal-Hydraulic Test Loop for Accident Simulation (ATLAS). This ISP-50 exercise has been performed in two consecutive phases: "blind" and "open" phases. Quantitative comparisons were performed using the Fast Fourier Transform Based Method (FFTBM) to compare the overall accuracy of the collected calculations. Great user effects resulting from the combination of the possible reasons were found in the blind phase, confirming that user effect is still one of the major issues in connection with the system thermal-hydraulic code application. Open calculations showed better prediction accuracy than the blind calculations in terms of average amplitude (AA) value. A total of nineteen organizations from eleven countries participated in this ISP-50 program and eight leading thermal-hydraulic system analysis codes were used: APROS, ATHLET, CATHARE, KORSAR, MARS-KS, RELAP5/MOD3.3, TECH-M-97, and TRACE.

Nonlinear finite element analysis of reinforced concrete corbels at both deterministic and probabilistic levels

  • Strauss, Alfred;Mordini, Andrea;Bergmeister, Konrad
    • Computers and Concrete
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    • v.3 no.2_3
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    • pp.123-144
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    • 2006
  • Reinforced concrete corbels are structural elements widely used in practical engineering. The complex response of these elements is described in design codes in a simplified manner. These formulations are not sufficient to show the real behavior, which, however, is an essential prerequisite for the manufacturing of numerous elements. Therefore, a deterministic and probabilistic study has been performed, which is described in this contribution. Real complex structures have been modeled by means of the finite element method supported primarily by experimental works. The main objective of this study was the detection of uncertainties effects and safety margins not captured by traditional codes. This aim could be fulfilled by statistical considerations applied to the investigated structures. The probabilistic study is based on advanced Monte Carlo simulation techniques and sophisticated nonlinear finite element formulations.

An Intrusion Detection Method by Tracing Root Privileged Processes (Root 권한 프로세스 추적을 통한 침입 탐지 기법)

  • Park, Jang-Su;Ahn, Byoung-Chul
    • The KIPS Transactions:PartC
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    • v.15C no.4
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    • pp.239-244
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    • 2008
  • It is not enough to reduce damages of computer systems by just patching vulnerability codes after incidents occur. It is necessary to detect and block intrusions by boosting the durability of systems even if there are vulnerable codes in systems. This paper proposes a robust real-time intrusion detection method by monitoring root privileged processes instead of system administrators in Linux systems. This method saves IP addresses of users in the process table and monitors IP addresses of every root privileged process. The proposed method is verified to protect vulnerable programs against the buffer overflow by using KON program. A configuration protocol is proposed to manage systems remotely and host IP addresses are protected from intrusions safely through this protocol.

A Code Block Cipher Method to Protect Application Programs From Reverse Engineering (응용프로그램 역분석 방지를 위한 코드블록 암호화 방법)

  • Jung, Dong-Woo;Kim, Hyong-Shik;Park, Joong-Gil
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.2
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    • pp.85-96
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    • 2008
  • One of the typical methods to prevent tampering and reverse engineering on executable codes is to encrypt them. This paper proposes a code block cipher method based on key chaining to encrypt the code. The block cipher by key chaining has been known to be inadequate for encrypting the code with control transfer, even though the key chaining has advantage of hiding the keys in blocks and making the individual keys different from block to block. This paper proposes a block transformation and duplication method to apply the block cipher by key chaining to the executable codes with control transfer instructions, and shows the idea works with the MIPS instruction set.

Criticality analysis of pyrochemical reprocessing apparatuses for mixed uranium-plutonium nitride spent nuclear fuel using the MCU-FR and MCNP program codes

  • P.A. Kizub ;A.I. Blokhin ;P.A. Blokhin ;E.F. Mitenkova;N.A. Mosunova ;V.A. Kovrov ;A.V. Shishkin ;Yu.P. Zaikov ;O.R. Rakhmanova
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.1097-1104
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    • 2023
  • A preliminary criticality analysis for novel pyrochemical apparatuses for the reprocessing of mixed uranium-plutonium nitride spent nuclear fuel from the BREST-OD-300 reactor was performed. High-temperature processing apparatuses, "metallization" electrolyzer, refinery remelting apparatus, refining electrolyzer, and "soft" chlorination apparatus are considered in this work. Computational models of apparatuses for two neutron radiation transport codes (MCU-FR and MCNP) were developed and calculations for criticality were completed using the Monte Carlo method. The criticality analysis was performed for different loads of fissile material into the apparatuses including overloading conditions. Various emergency situations were considered, in particular, those associated with water ingress into the chamber of the refinery remelting apparatus. It was revealed that for all the considered computational models nuclear safety rules are satisfied.

Increased Prevalence of Chronic Disease in Back Pain Patients Living in Car-dependent Neighbourhoods in Canada: A Cross-sectional Analysis

  • Zeglinski-Spinney, Amy;Wai, Denise C.;Phan, Philippe;Tsai, Eve C.;Stratton, Alexandra;Kingwell, Stephen P.;Roffey, Darren M.;Wai, Eugene K.
    • Journal of Preventive Medicine and Public Health
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    • v.51 no.5
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    • pp.227-233
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    • 2018
  • Objectives: Chronic diseases, including back pain, result in significant patient morbidity and societal burden. Overall improvement in physical fitness is recommended for prevention and treatment. Walking is a convenient modality for achieving initial gains. Our objective was to determine whether neighbourhood walkability, acting as a surrogate measure of physical fitness, was associated with the presence of chronic disease. Methods: We conducted a cross-sectional study of prospectively collected data from a prior randomized cohort study of 227 patients referred for tertiary assessment of chronic back pain in Ottawa, ON, Canada. The Charlson Comorbidity Index (CCI) was calculated from patient-completed questionnaires and medical record review. Using patients' postal codes, neighbourhood walkability was determined using the Walk Score, which awards points based on the distance to the closest amenities, yielding a score from 0 to 100 (0-50: car-dependent; 50-100: walkable). Results: Based on the Walk Score, 134 patients lived in car-dependent neighborhoods and 93 lived in walkable neighborhoods. A multivariate logistic regression model, adjusted for age, gender, rural postal code, body mass index, smoking, median household income, percent employment, pain, and disability, demonstrated an adjusted odds ratio of 2.75 (95% confidence interval, 1.16 to 6.53) times higher prevalence for having a chronic disease for patients living in a car-dependent neighborhood. There was also a significant dose-related association (p=0.01; Mantel-Haenszel chi-square=6.4) between living in car-dependent neighbourhoods and more severe CCI scores. Conclusions: Our findings suggest that advocating for improved neighbourhood planning to permit greater walkability may help offset the burden of chronic disease.

A strategy for effectively applying a control flow obfuscation to programs (제어 흐름 난독화를 효과적으로 수행하기 위한 전략)

  • Kim, Jung-Il;Lee, Eun-Joo
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.6
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    • pp.41-50
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    • 2011
  • Code obfuscation has been proposed to protect codes in a program from malicious software reverse engineering. It converts a program into an equivalent one that is more difficult to understand the program. Code obfuscation has been classified into various obfuscation technique such as layout, data, control, by obfuscating goals. In those obfuscation techniques, control obfuscation is intended to complicate the control flow in a program to protect abstract information of control flow. For protecting control flow in a program, various control obfuscation transformation techniques have been proposed. However, strategies for effectively applying a control flow obfuscation to program have not been proposed yet. In this paper, we proposed a obfuscation strategy that effectively applies a control flow obfuscation transformation to a program. We conducted experiment to show that the proposed obfuscation strategy is useful for applying a control flow transformation to a program.

Automated Detecting and Tracing for Plagiarized Programs using Gumbel Distribution Model (굼벨 분포 모델을 이용한 표절 프로그램 자동 탐색 및 추적)

  • Ji, Jeong-Hoon;Woo, Gyun;Cho, Hwan-Gue
    • The KIPS Transactions:PartA
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    • v.16A no.6
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    • pp.453-462
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    • 2009
  • Studies on software plagiarism detection, prevention and judgement have become widespread due to the growing of interest and importance for the protection and authentication of software intellectual property. Many previous studies focused on comparing all pairs of submitted codes by using attribute counting, token pattern, program parse tree, and similarity measuring algorithm. It is important to provide a clear-cut model for distinguishing plagiarism and collaboration. This paper proposes a source code clustering algorithm using a probability model on extreme value distribution. First, we propose an asymmetric distance measure pdist($P_a$, $P_b$) to measure the similarity of $P_a$ and $P_b$ Then, we construct the Plagiarism Direction Graph (PDG) for a given program set using pdist($P_a$, $P_b$) as edge weights. And, we transform the PDG into a Gumbel Distance Graph (GDG) model, since we found that the pdist($P_a$, $P_b$) score distribution is similar to a well-known Gumbel distribution. Second, we newly define pseudo-plagiarism which is a sort of virtual plagiarism forced by a very strong functional requirement in the specification. We conducted experiments with 18 groups of programs (more than 700 source codes) collected from the ICPC (International Collegiate Programming Contest) and KOI (Korean Olympiad for Informatics) programming contests. The experiments showed that most plagiarized codes could be detected with high sensitivity and that our algorithm successfully separated real plagiarism from pseudo plagiarism.