• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1333-1340
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• 2005

This paper is based on the study to reduce a system panic state. A panic state could be caused by a programmer or an administrator's careless mistake. The proposed hardening Operating System of this paper stops the process which is running in the kernel with an error. The error process for the value type and the address type of a certain variable have to be restored. Installed with kernel hardening, Operating System checks the recovery possibility of the process first and then restores the process which can be recovered. When it is possible to recover the kernel code with an error, it is to be recovered in ASSERT() function.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.961-969
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• 2004

A panic state is often caused by careless computer control. It could be also caused by a kernel programmer's mistake. It can make a big problem in computer system when it happens a lot. When a panic occurs, the process of the panic state has to be checked, then if it can be restored, operating system restores it, but if not, operating system runs the panic function to stop the system in the kernel hardening O.S. To decide recovery of the process, the type of the panic for the present process should be checked. 1'he value type and the address type have to restore the process. If the system process is in a panic state, the system should be designed to shutdown hardening function In the Linux operating system. So it has to decide whether the process should be restored or not before going to the panic state.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.5
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• pp.53-61
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• 2002

In this paper, we will introduce a design of key recovery based on XML can be used in B2B environment. XML Digital Signature and XML Encryption that are defied recently as standards by W3C(World Wide Web Consortium) are deployed to sign/verify or encrypt/decrypt documents for electronic commerce and keys to store/load at/from key recovery server. The result of signature or encryption is always an XML document and all messages used in this key recovery system are also XML documents. It enables to adapt transparently this key recovery system to legacy XML applications and electronic commerce platforms based on XML. And its method for key recovery is key escrow. One of the characteristics of this key recovery is that one enterprise can recover keys of some documents for electronic commerce from external key recovery system in other enterprises related with them and also recover keys from owns.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.71-77
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• 2008

This paper presents a methodology for recovering the industrial radiographic images from the effects of nonlinear distortion. Analytical approach based on the inverse square law and Beer's law is developed in order to improve a mathematic model of nonlinear type. The geometric effect due to dimensions of the radioactive source appeals on the digitized images. The relation that expresses parameters values(angle, position, absorption coefficient, length, width and pixel account) is defined in this model, matching with the sample image. To perform the search for image recovery most similar to the model, a correction procedure is designed. The application of this method on the radiographic images of steel tubes is shown and recovered results are discussed.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.280-289
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• 2003

Deadlock recovery-based routing algorithms in wormhole networks have gained attraction due to low hardware complexity and high routing adaptability Progressive deadlock recovery techniques require a few dedicated resources to transmit deadlocked packets rather than killing them. Selection of deadlocked packets is primarily based on time-out value which should be carefully determined considering various traffic patterns or packet length. By its nature, current techniques using time-out accompany unignorable number of false deadlock detections especially in a heavy-loaded network or with long packet size. Moreover, when a deadlock occurs, more than one packet may be marked as deadlocked, which saturate the resources allocated for recovery. This paper proposes more accurate deadlock detection scheme which does not make use of time-out to declare deadlock. The proposed scheme reduces the probability to detect false deadlocks considerably. Furthermore, a single message is selected as deadlocked for each cycle of blocked messages, thereby eliminating recovery overheads.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.31-40
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• 1995

The purpose of this study was to analyze the process of natural plant establishment and revegetation on the slopes of landslide scars, both untreated(l4 plots) and treated plots (14 plots) with rehabilitation measures in 1993 and 1994 at Yongin Hwaseong-gun region. While total of 61 species were identified at surveyed sites. in the region, the pioneer species on landslide scars were Lespedeza cyrtobotrya, Arundinella hirta, Artemisia princeps, Pteridium acquilinum, Erigeron canadensis. Rubus crataegifolius, Stephanandra incisa etc. The species diversity (H') and evenness(E') of the untreated scars were greater than those of the treated scars. Similarity indices in the untreated scars were higher than those in the treated scars, and succession indices showed similar value in both areas. As a conclusion, this study shows that the untreated scars were more influenced by the around-vegetation, and the native vegetations(plants) like Lespedeza cyrtobotrya, Arundinella hirta. Miscanthus sinensis, Artemisia princeps, Pteridium acquilinum, Erigeron canadensis. Rubus crataegifolius, Stephanandra incisa ete. could be more effectively used as plant vegetation for rehabilitation of landslide scars.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.144-148
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• 2009

지구온난화로 인한 홍수빈도 및 강우강도의 증가로 홍수피해의 규모는 더욱 증가하고 있다. 그리고 방재대책도 발생한 피해에 대한 복구를 주된 정책으로 하던 소극적 자세에서 벗어나 과학적 공학적 접근을 통해 재해에 대응할 수 있는 기술을 개발하는 적극적 홍수방어 체계를 구축하고 있다. 또한, 설계빈도의 무조건적인 상향조정에 따른 확정론적인 방법에 의존하기 보다는 추계학적 방법을 도입한 수문량 확충 및 매개변수의 불확실성 분석이 필요성이 대두되고 있는 실정이다. 일반적으로 수공구조물의 설계 시에는 설계홍수량을 사용하는데 이는 홍수특성, 홍수발생빈도, 홍수발생 가능성 등을 수공구조물의 규모와 파괴 시 예상되는 피해 정도에 따라 요구되는 안전성을 함께 고려해 수공구조물의 설계기준으로 활용된다. 설계홍수량은 지속시간과 재현기간을 사전에 지정하여 빈도분석을 통해 설계강우량을 산정하고 이를 강우-유출 분석을 함으로써 산정된다. 설계강우량은 빈도분석을 위해 선택된 강우형태에 따른 수문학적 무작위성을 포함하고 있다. 따라서 시간적 변동을 고려한 적절한 강우양상 형태의 선택은 수문학적으로 안전한 수공구조물의 설계 및 평가에 매우 큰 영향을 미친다. 현재의 경우는 강우형태에 대한 선택이 경험에 의해 임의로 이루어지므로, 토목공학자는 여러 가지 발생 가능한 강우형태에 따른 시간적 분포에 대해 고려해야 한다. 본 연구에서는 Huff분위에 따른 무차원 누가 강우곡선을 이용해 강우변동양상 생성을 위한 제약조건을 log-ratio 변환을 이용해 극복하였으며, 결과의 통계 특성치를 Johnson 분포를 통해 표준정규분포로 변환시켰다. 무작위 변수 발생 후 강우양상별 표준정규값의 상관행렬을 이용하여 상관성이 있는 무작위변수로 변환하였다. 얻어진 상관성을 갖는 무작위변수는 log-ratio 역변환을 통해 상관성을 갖는 변수로 재변환해서 무차원화된 강우곡선을 얻을 수 있었다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.3
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• pp.201-207
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• 2021

Deep learning, a type of machine learning, performs learning while changing the weights as it progresses through each learning process. Tensor Flow and Keras provide the results of the end of the learning in graph form. Thus, If an error occurs, the result must be discarded. Consequently, existing technologies provide a function to roll back learning results, but the rollback function is limited to results up to five times. Moreover, they applied the concept of MLOps to track the deep learning process, but no rollback capability is provided. In this paper, we construct a system that manages the intermediate value of the learning process by blockchain to record the intermediate learning process and can rollback in the event of an error. To perform the functions of blockchain, the deep learning process and the rollback of learning results are designed to work by writing Smart Contracts. Performance evaluation shows that, when evaluating the rollback function of the existing deep learning method, the proposed method has a 100% recovery rate, compared to the existing technique, which reduces the recovery rate after 6 times, down to 10% when 50 times. In addition, when using Smart Contract in Ethereum blockchain, it is confirmed that 1.57 million won is continuously consumed per block creation.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.1-8
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• 1999

This paper presents a new algorithm for surface segmentation and feature description. In the first stage of proposed algorithm, the signature of an edge image of object is extracted. The signature technique represents a surface using the distance from the mass center to the boundary of the image as a function of angle rotating counterclockwise. If there exists a range in the angle axis where more than two signatures form a closed curve, we can conclude there is a surface inside the range. Using this feature of the signature, surface can be segmented. The surface features such as number of vertices, number of edges, convex and type of surface can also be extracted from segmented surfaces. This algorithm has distinguished advantages; it can easily recover the lost part in the edge image using the curve fitting method; it extracts surface features correctly regardless of the rotation of the surface in 3-D space.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.2
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• pp.75-86
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• 2002

The selection of the optimal checkpointing interval has been a very critical issue to implement a checkpointing recovery scheme for the fault tolerant distributed system. This paper presents a new scheme that allows a process to select the proper checkpointing interval dynamically. A process in the system evaluates the cost of checkpointing and possible rollback for each checkpointing interval and selects the proper time interval for the next checkpointing Unlike the other scheme, the overhead incurred by both of the checkpointing and rollback activities are considered for the cost evaluation and current communication pattern is reflected in the selection of the checkpointing interval. Moreover, the proposed scheme requires no extra message communication for the checkpointing interval selection and can easily be incorporated into the existing checkpointing coordination schemes.