• Title/Summary/Keyword: Time complexity

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Fast RSA Montgomery Multiplier and Its Hardware Architecture (고속 RSA 하드웨어 곱셈 연산과 하드웨어 구조)

  • Chang, Nam-Su;Lim, Dae-Sung;Ji, Sung-Yeon;Yoon, Suk-Bong;Kim, Chang-Han
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.1
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    • pp.11-20
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    • 2007
  • A fast Montgomery multiplication occupies important to the design of RSA cryptosystem. Montgomery multiplication consists of two addition, which calculates using CSA or RBA. In terms of CSA, the multiplier is implemented using 4-2 CSA o. 5-2 CSA. In terms of RBA, the multiplier is designed based on redundant binary system. In [1], A new redundant binary adder that performs the addition between two binary signed-digit numbers and apply to Montgomery multiplier was proposed. In this paper, we reconstruct the logic structure of the RBA in [1] for reducing time and space complexity. Especially, the proposed RB multiplier has no coupler like the RBA in [1]. And the proposed RB multiplier is suited to binary exponentiation as modified input and output forms. We simulate to the proposed NRBA using gates provided from SAMSUNG STD130 $0.18{\mu}m$ 1.8V CMOS Standard Cell Library. The result is smaller by 18.5%, 6.3% and faster by 25.24%, 14% than 4-2 CSA, existing RBA, respectively. And Especially, the result is smaller by 44.3% and faster by 2.8% than the RBA in [1].

Past, Present and Future of Geospatial Scheme based on Topo-Climatic Model and Digital Climate Map (소기후모형과 전자기후도를 기반으로 한 지리공간 도식의 과거, 현재 그리고 미래)

  • Kim, Dae-Jun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.268-279
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    • 2021
  • The geospatial schemes based on topo-climatology have been developed to produce digital climate maps at a site-specific scale. Their development processes are reviewed here to derive the needs for new schemes in the future. Agricultural and forestry villages in Korea are characterized by complexity and diversity in topography, which results in considerably large spatial variations in weather and climate over a small area. Hence, the data collected at a mesoscale through the Automated Synoptic Observing System (ASOS) operated by the Korea Meteorological Administration (KMA) are of limited use. The geospatial schemes have been developed to estimate climate conditions at a local scale, e.g., 30 m, lowering the barriers to deal with the processes associated with production in agricultural and forestry industries. Rapid enhancement of computing technologies allows for near real-time production of climate information at a high-resolution even in small catchment areas and the application to future climate change scenarios. Recent establishment of the early warning service for agricultural weather disasters can provide growth progress and disaster forecasts for cultivated crops on a farm basis. The early warning system is being expanded worldwide, requiring further advancement in geospatial schemes and digital climate mapping.

Web-based Disaster Operating Picture to Support Decision-making (의사결정 지원을 위한 웹 기반 재난정보 표출 방안)

  • Kwon, Youngmok;Choi, Yoonjo;Jung, Hyuk;Song, Juil;Sohn, Hong-Gyoo
    • Korean Journal of Remote Sensing
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    • v.38 no.5_2
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    • pp.725-735
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    • 2022
  • Currently, disasters occurring in Korea are characterized by unpredictability and complexity. Due to these features, property damage and human casualties are increasing. Since the initial response process of these disasters is directly related to the scale and the spread of damage, optimal decision-making is essential, and information of the site must be obtained through timely applicable sensors. However, it is difficult to make appropriate decisions because indiscriminate information is collected rather than necessary information in the currently operated Disaster and Safety Situation Office. In order to improve the current situation, this study proposed a framework that quickly collects various disaster image information, extracts information required to support decision-making, and utilizes it. To this end, a web-based display system and a smartphone application were proposed. Data were collected close to real time, and various analysis results were shared. Moreover, the capability of supporting decision-making was reviewed based on images of actual disaster sites acquired through CCTV, smartphones, and UAVs. In addition to the reviewed capability, it is expected that effective disaster management can be contributed if institutional mitigation of the acquisition and sharing of disaster-related data can be achieved together.

Explanable Artificial Intelligence Study based on Blockchain Using Point Cloud (포인트 클라우드를 이용한 블록체인 기반 설명 가능한 인공지능 연구)

  • Hong, Sunghyuck
    • Journal of Convergence for Information Technology
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    • v.11 no.8
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    • pp.36-41
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    • 2021
  • Although the technology for prediction or analysis using artificial intelligence is constantly developing, a black-box problem does not interpret the decision-making process. Therefore, the decision process of the AI model can not be interpreted from the user's point of view, which leads to unreliable results. We investigated the problems of artificial intelligence and explainable artificial intelligence using Blockchain to solve them. Data from the decision-making process of artificial intelligence models, which can be explained with Blockchain, are stored in Blockchain with time stamps, among other things. Blockchain provides anti-counterfeiting of the stored data, and due to the nature of Blockchain, it allows free access to data such as decision processes stored in blocks. The difficulty of creating explainable artificial intelligence models is a large part of the complexity of existing models. Therefore, using the point cloud to increase the efficiency of 3D data processing and the processing procedures will shorten the decision-making process to facilitate an explainable artificial intelligence model. To solve the oracle problem, which may lead to data falsification or corruption when storing data in the Blockchain, a blockchain artificial intelligence problem was solved by proposing a blockchain-based explainable artificial intelligence model that passes through an intermediary in the storage process.

Improved Method for Learning Context-Free Grammar using Tabular representation

  • Jung, Soon-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.2
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    • pp.43-51
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    • 2022
  • In this paper, we suggest the method to improve the existing method leaning context-free grammar(CFG) using tabular representation(TBL) as a chromosome of genetic algorithm in grammatical inference and show the more efficient experimental result. We have two improvements. The first is to improve the formula to reflect the learning evaluation of positive and negative examples at the same time for the fitness function. The second is to classify partitions corresponding to TBLs generated from positive learning examples according to the size of the learning string, proceed with the evolution process by class, and adjust the composition ratio according to the success rate to apply the learning method linked to survival in the next generation. These improvements provide better efficiency than the existing method by solving the complexity and difficulty in the crossover and generalization steps between several individuals according to the size of the learning examples. We experiment with the languages proposed in the existing method, and the results show a rather fast generation rate that takes fewer generations to complete learning with the same success rate than the existing method. In the future, this method can be tried for extended CYK, and furthermore, it suggests the possibility of being applied to more complex parsing tables.

Analysis of Grover Attack Cost and Post-Quantum Security Strength Evaluation for Lightweight Cipher SPARKLE SCHWAEMM (경량암호 SPARKLE SCHWAEMM에 대한 Grover 공격 비용 분석 및 양자 후 보안 강도 평가)

  • Yang, Yu Jin;Jang, Kyung Bae;Kim, Hyun Ji;Song, Gyung Ju;Lim, Se Jin;Seo, Hwa Jeong
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.12
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    • pp.453-460
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    • 2022
  • As high-performance quantum computers are expected to be developed, studies are being actively conducted to build a post-quantum security system that is safe from potential quantum computer attacks. When the Grover's algorithm, a representative quantum algorithm, is used to search for a secret key in a symmetric key cryptography, there may be a safety problem in that the security strength of the cipher is reduced to the square root. NIST presents the post-quantum security strength estimated based on the cost of the Grover's algorithm required for an attack of the cryptographic algorithm as a post-quantum security requirement for symmetric key cryptography. The estimated cost of Grover's algorithm for the attack of symmetric key cryptography is determined by the quantum circuit complexity of the corresponding encryption algorithm. In this paper, the quantum circuit of the SCHWAEMM algorithm, AEAD family of SPARKLE, which was a finalist in NIST's lightweight cryptography competition, is efficiently implemented, and the quantum cost to apply the Grover's algorithm is analyzed. At this time, the cost according to the CDKM ripple-carry adder and the unbounded Fan-Out adder is compared together. Finally, we evaluate the post-quantum security strength of the lightweight cryptography SPARKLE SCHWAEMM algorithm based on the analyzed cost and NIST's post-quantum security requirements. A quantum programming tool, ProjectQ, is used to implement the quantum circuit and analyze its cost.

Preliminary Uncertainty Analysis to Build a Data-Driven Prediction Model for Water Quality in Paldang Dam (팔당댐 유역의 데이터 기반 수질 예측 모형 구성을 위한 사전 불확실성 분석)

  • Lee, Eun Jeong;Keum, Ho Jun
    • Ecology and Resilient Infrastructure
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    • v.9 no.1
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    • pp.24-35
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    • 2022
  • For water quality management, it is necessary to continuously improve the forecasting by analyzing the past water quality, and a Data-driven model is emerging as an alternative. Because the Data-driven model is built based on a wide range of data, it is essential to apply the correlation analysis method for the combination of input variables to obtain more reliable results. In this study, the Gamma Test was applied as a preceding step to build a faster and more accurate data-driven water quality prediction model. First, a physical-based model (HSPF, EFDC) was operated to produce daily water quality reflecting the complexity of the watershed according to various hydrological conditions for Paldang Dam. The Gamma Test was performed on the water quality at the water quality prediction site (Paldangdam2) and major rivers flowing into the Paldang Dam, and the method of selecting the optimal input data combination was presented through the analysis results (Gamma, Gradient, Standar Error, V-Ratio). As a result of the study, the selection criteria for a more efficient combination of input data that can save time by omitting trial and error when building a data-driven model are presented.

The Future of NVH Research - A Challenge by New Powertrains

  • Genuit, Ing. K.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.05a
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    • pp.48-48
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    • 2010
  • Sound quality and NVH-issues(Noise, Vibration and Harshness) of vehicles has become very important for car manufacturers. It is interpreted as among the most relevant factors regarding perceived product quality, and is important in gaining market advantage. The general sound quality of vehicles was gradually improved over the years. However, today the development cycles in the automotive industry are constantly reduced to meet the customers' demands and to react quickly to market needs. In addition, new drive and fuel concepts, tightened ecological specifications, increase of vehicle classes and increasing diversification(increasing market for niche vehicles), etc. challenge the acoustic engineers trying to develop a pleasant, adequate, harmonious passenger cabin sound. Another aspect concerns the general pressure for reducing emission and fuel consumption, which lead to vehicle weight reductions through material changes also resulting in new noise and vibration conflicts. Furthermore, in the context of alternative powertrains and engine concepts, the new objective is to detect and implement the vehicle sound, tailored to suit the auditory expectations and needs of the target group. New questions must be answered: What are appropriate sounds for hybrid or electric vehicles? How are new vehicle sounds perceived and judged? How can customer-oriented, client-specific target sounds be determined? Which sounds are needed to fulfil the driving task, and so on? Thus, advanced methods and tools are necessary which cope with the increasing complexity of NVH-problems and conflicts and at the same time which cope with the growing expectations regarding the acoustical comfort. Moreover, it is exceedingly important to have already detailed and reliable information about NVH-issues in early design phases to guarantee high quality standards. This requires the use of sophisticated simulation techniques, which allow for the virtual construction and testing of subsystems and/or the whole car in early development stages. The virtual, testing is very important especially with respect to alternative drive concepts(hybrid cars, electric cars, hydrogen fuel cell cars), where complete new NVH-problems and challenges occur which have to be adequately managed right from the beginning. In this context, it is important to mention that the challenge is that all noise contributions from different sources lead to a harmonious, well-balanced overall sound. The optimization of single sources alone does not automatically result in an ideal overall vehicle sound. The paper highlights modern and innovative NVH measurement technologies as well as presents solutions of recent NVH tasks and challenges. Furthermore, future prospects and developments in the field of automotive acoustics are considered and discussed.

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FunRank: Finding 1-Day Vulnerability with Call-Site and Data-Flow Analysis (FunRank: 함수 호출 관계 및 데이터 흐름 분석을 통한 공개된 취약점 식별)

  • Jaehyu Lee;Jihun Baek;Hyungon Moon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.2
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    • pp.305-318
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    • 2023
  • The complexity of software products led many manufacturers to stitch open-source software for composing a product. Using open-source help reduce the development cost, but the difference in the different development life cycles makes it difficult to keep the product up-to-date. For this reason, even the patches for known vulnerabilities are not adopted quickly enough, leaving the entire product under threat. Existing studies propose to use binary differentiation techniques to determine if a product is left vulnerable against a particular vulnerability. Despite their effectiveness in finding real-world vulnerabilities, they often fail to locate the evidence of a vulnerability if it is a small function that usually is inlined at compile time. This work presents our tool FunRank which is designed to identify the short functions. Our experiments using synthesized and real-world software products show that FunRank can identify the short, inlined functions that suggest that the program is left vulnerable to a particular vulnerability.

A study on the application of the agricultural reservoir water level recognition model using CCTV image data (농업용 저수지 CCTV 영상자료 기반 수위 인식 모델 적용성 검토)

  • Kwon, Soon Ho;Ha, Changyong;Lee, Seungyub
    • Journal of Korea Water Resources Association
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    • v.56 no.4
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    • pp.245-259
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    • 2023
  • The agricultural reservoir is a critical water supply system in South Korea, providing approximately 60% of the agricultural water demand. However, the reservoir faces several issues that jeopardize its efficient operation and management. To address this issues, we propose a novel deep-learning-based water level recognition model that uses CCTV image data to accurately estimate water levels in agricultural reservoirs. The model consists of three main parts: (1) dataset construction, (2) image segmentation using the U-Net algorithm, and (3) CCTV-based water level recognition using either CNN or ResNet. The model has been applied to two reservoirs G-reservoir and M-reservoir with observed CCTV image and water level time series data. The results show that the performance of the image segmentation model is superior, while the performance of the water level recognition model varies from 50 to 80% depending on water level classification criteria (i.e., classification guideline) and complexity of image data (i.e., variability of the image pixels). The performance of the model can be improved if more numbers of data can be collected.