• 한국농공학회논문집
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• 제52권2호
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• pp.59-66
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• 2010

This study was performed to develop the embankment protection method that can reduce demage by prevention of embankment loss and collapse from overflow due to heavy rain and flood. For overflow test, model dam was prepared and embankment behaviors were monitored with the established piezometer and strain meter during overflow. As a result of overflow test for model dam, in case of embankment without waterproof mat, the lower end of embankment was collapsed within 40 seconds after beginning of overflow. On the other hand, in case of embankment with waterproof mat, embankment collapse didn't occurred during overflow. Accordingly, establishment of waterproof mat for embankment showed that be absolutely effective for the embankment protection during overflow in reservoir. Also, it showed that the minimum establishment range of waterproof mat to prevent embankment collapse in reservoir is from maximum storage level to the lower end of embankment.

• 한국해양공학회지
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• 제34권2호
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• pp.128-135
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• 2020

When high waves and storm surge strike simultaneously, the characteristics of the fluid field change drastically from overtopping according to the wave runup height to overflow through a transition state that combines overtopping and overflows. However, an estimation model or evaluation method has not yet been established because there is not enough engineering data. This study developed a wave overtopping-overflow transition model based on a full-scale experiment involving wave overtopping and overflow transition, which appropriately reproduced the effect of waves or the temporal change in inundation flow. Using this model to perform a calculation for the wave overtopping and overflow transition process under typical circumstances, this study determined the wave runup height and features of the inundation flow under time series changes as an example.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (1)
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• pp.608-610
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• 2000

Buffer Overflow는 가장 핵심적인 해킹기법중의 하나이다. 현재 해킹피해의 대부분을 차지하며 local attack뿐 아니라 remote attack까지 가능하므로 이를 이해함은 보안을 이해하는 차원에서 매우 중요하다. 본 논문에서는 Buffer Overflow의 원리와 최근 발생한 시스템의 해킹 형태를 살펴보고, 이를 방지할 수 있는 기법들을 분석하여 Buffer Overflow에 대응할 수 있는 모습을 그려보고자 한다.

• 디지털산업정보학회논문지
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• 제6권1호
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• pp.105-114
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• 2010

C language is frequently used to develop application and system programs. However, programs using C language are vulnerable to buffer overflow attacks. To prevent buffer overflow, programmers have to check boundaries of buffer areas when they develop programs. But vulnerable programs frequently result from improper programming habits and mistakes of programmers. Existing researches for preventing buffer overflow attacks only inform programmers of warnings about vulnerabilities and not remove vulnerabilities in advance so that the programs still include vulnerabilities. In this paper, we propose a function translator which prevents creating programs including buffer overflow vulnerabilities. To prevent creating binary from source including vulnerabilities, the proposed translator searches vulnerable functions which cause buffer overflows, and converts them into secure functions. Accordingly, developing vulnerable programs by programmers which lack in knowledge on security can be prevented.

• 한국농공학회지
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• 제6권2호
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• pp.816-825
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• 1964

1. Outline: The flow of the siphon spillway is very intricate and affected by vacuous condition. It is an intresting problem to make vacuum rapidly in_siphon, i.e, to provoke the perfect siphonaoge with the lowest water-level of overflow. The hydraulic experiments of siphon spillway have practiced at the Masan Lake, Haenam, the province of Junnam and gained rational and economical results which cannot be odtained by calculation. 2. Experiment: The model scale was a half of that of the prototype. 3. Results and discussion: In the experiments of 14 runs, washing, overflow water level, outlet, water level of cushion, phenomenon of water flying and water pressure of every part, etc. were studied. a) The relation of overflow water-level at siphon inlet and deflector When the elevation of the deflector is 10. 65m and the form of deflector O.4m long is the hypotenuse of an $45^{\circ}$ isosceles triangle, the over flow water-level is the minimum, i. e. the siphonage was excellent. There is no effect by the rising of overflow water-Ievel between 11.95m to 1O.65m of deflector elevation (in the first plan, it is 11.05m). But the overflow water-level rises remarkably in the outside region of the above limits. b) The relation of overflow water-level, the length of cushion and standard height of the base. The reduction of the length of cushion brings the rising of overflow waterlevel, and the rising of the standard height of the base brings the rising of overflow water level. For the long cushion length and low standard height of the base, it cannot be expeted to have the falling of overflow water-level. The most satisfactory data were obtained at 5.20m of the base standard height and 6.1m of the length of cushion. The first vah,le planned was 5.70 m and 4.30m.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.207-212
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• 2021

A buffer overflow attack is carried out to subvert privileged program functions to gain control of the program and thus control the host. Buffer overflow attacks should be prevented by risk managers by eradicating and detecting them before the software is utilized. While calculating the size, correct variables should be chosen by risk managers in situations where fixed-length buffers are being used to avoid placing excess data that leads to the creation of an overflow. Metamorphism can also be used as it is capable of protecting data by attaining a reasonable resistance level [1]. In addition, risk management teams should ensure they access the latest updates for their application server products that support the internet infrastructure and the recent bug reports [2]. Scanners that can detect buffer overflows' flaws in their custom web applications and server products should be used by risk management teams to scan their websites. This paper presents an experiment of buffer overflow vulnerability and attack. The aims to study of a buffer overflow mechanism, types, and countermeasures. In addition, to comprehend the current detection plus prevention approaches that can be executed to prevent future attacks or mitigate the impacts of similar attacks.

• Communications for Statistical Applications and Methods
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• 제8권1호
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• pp.257-269
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• 2001

The simulation is used to estimate an overflow probability in a stable parallel network with coupled inputs. Since the general simulation needs extremely many trials to obtain such a small probability, the fast simulation is proposed to reduce trials instead. By using the Cramer’s theorem, we first obtain an optimally changed measure under which the variance of the estimator is minimized. Then, we use it to derive an importance sampling estimator of the overflow probability which enables us to perform the fast simulation.

• Journal of the Korean Statistical Society
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• 제32권4호
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• pp.359-371
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• 2003

We consider the probability that the total population of a stable Jackson network reaches a given large value. By using the fluid limit of the reversed network, we derive new upper and lower bounds on this probability, which are sharper than those in Glasserman and Kou (1995). In particular, the improved lower bound is useful for analyzing the performance of an importance sampling estimator for the overflow probability in Jackson tandem networks. Bounds on the expected time to overflow are also obtained.

• International Journal of Ocean System Engineering
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• 제2권4호
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• pp.200-208
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• 2012

Surge overflow may cause damage on earthen levees. Levee strengthened on the levee crest and landward-side slope can provide protection against the erosion damage induced by surge overflow. In this paper, surge overflow of a roller compacted concrete RCC strengthened levee was studied in a purely Lagrangian and meshless approach, the smoothed particle hydrodynamics (SPH) method. After verifying the developed model with analytical solution and comparing the results with full-scale experimental data, the roughness and erosion parameters were calibrated. The water thickness, flow velocity, and erosion depth at crest, landward-side slope and toe were calculated. The characteristics of flow hydraulics and erosion on the RCC strengthened levee are given. The results indicate that the RCC strengthened levee can resist erosion damage for a long period.

• 한국조리학회지
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• 제13권1호
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• pp.204-211
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• 2007

In order to develop a pot lid that would not overflow, three parts were created, each different in size. One cover (A") had a small hole (dia. 10 cm) for the vapor to escape (dia. about 2.5 mm). Another, cover A' had a medium-sized hole (dia. about 5 cm) for the vapor to escape. Cover A (dia. 300 mm, $120\;mm^H$) had a large hole (dia. 100 mm) for the vapor to escape. Because the new cover was partially open while soy paste solution cooking, it showed that it could not only prevent overflow, but also extend the burning approaching and salinity increase time, reducing both cooking time and the amount of energy necessary to cook.