• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.2
• /
• pp.243-252
• /
• 2023

As an efficient key recovery attack on SIDH/SIKE was proposed, CSIDH is drawing attention again. CSIDH is an isogeny-based key exchange algorithm that is safe against known attacks to date, and provide efficient NIKE by modernizing CRS scheme. In this paper, we firstly present the optimized implementation of CSIDH-512 on ARM Cortex-M7. We use three-level hybrid Montgomery reduction and present the results of our implementation, limitations, and future research directions. This is a CSIDH implementation in 32-bit embedded devices that has not been previously presented, and it is expected that the results of this paper will be available to implement CSIDH and derived cryptographic algorithms in various embedded environments in the future.

• Korean Journal of Agricultural Science
• /
• v.48 no.4
• /
• pp.1015-1026
• /
• 2021

The objective of this study was to determine amino acid and protein contents of brown and milled non-glutinous rice of 13 cultivars in Korea. Protein contents of MRs (milled rices) were in order of Haepum (7.27%) > Hanareum No. 4 (7.14%) > Odae (6.84%). Protein contents of BRs (brown rices) were in order of Haepum (7.68%) > Odae (7.63%) > Hanareum No. 4 (7.60%). The amino acid content was the highest in Haepum (MR 5.76%, BR 6.49%), followed by Haedeul (MR 5.71%, BR 6.30%), and Odae (MR 5.63%, BR 6.29%). The essential amino acid contents of non-glutinous rices were in order of Haepum (MR 2.34%, BR 2.57%) > Haedeul (MR 2.31%, BR 2.48%) > Odae (MR 2.20%, BR 2.56%). The contents of amino acid and protein in BRs were considerably higher than those in MRs. Protein and most of amino acid contents were higher in Haepum than the other cultivars. The certificated reference material (CRM) 1849a (infant/adults nutritional formular) from National Institute of Standard and Technology (NIST) was used as the test sample to determine the precision and accuracy of the analytical method. The regression analyses revealed good correlations (correlation coefficient), greater than 0.99. The recovery values of the amino acids ranged from 93.17 to 99.59%. The limit of detection (LODs) ranged from 0.01 - 0.07 mg·100 g^-1 and the limit of quantitation (LOQs) ranged from 0.03 - 0.21 mg·100 g^-1 for all analytes.

• Wind and Structures
• /
• v.36 no.6
• /
• pp.393-404
• /
• 2023

Skewness and kurtosis are important higher-order statistics for simulating non-Gaussian wind pressure series on low-rise buildings, but their predictions are less studied in comparison with those of the low order statistics as mean and rms. The distribution gradients of skewness and kurtosis on roofs are evidently higher than those of mean and rms, which increases their prediction difficulty. The conventional artificial neural networks (ANNs) used for predicting mean and rms show unsatisfactory accuracy in predicting skewness and kurtosis owing to the limited capacity of shallow learning of ANNs. In this work, the deep neural networks (DNNs) model with the ability of deep learning is introduced to predict the skewness and kurtosis on a low-rise building. For obtaining the optimal generalization of the DNNs model, the hyper parameters are automatically determined by Bayesian Optimization (BO). Moreover, for providing a benchmark for future studies on predicting higher order statistics, the data sets for training and testing the DNNs model are extracted from the internationally open NIST-UWO database, and the prediction errors of all taps are comprehensively quantified by various error metrices. The results show that the prediction accuracy in this study is apparently better than that in the literature, since the correlation coefficient between the predicted and experimental results is 0.99 and 0.75 in this paper and the literature respectively. In the untrained cornering wind direction, the distributions of skewness and kurtosis are well captured by DNNs on the whole building including the roof corner with strong non-normality, and the correlation coefficients between the predicted and experimental results are 0.99 and 0.95 for skewness and kurtosis respectively.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.08a
• /
• pp.110-110
• /
• 2020

꽃을 우려내어 차로 마시는 꽃차(flower tea)는 꽃이 가진 색과 향, 맛과 모양을 즐길 수 있어 최근 수요가 급증하고 있다. 본 연구는 매화(Prunus mume), 장미(Rosa spp.), 그리고 해당화(Rosa rugosa) 등 3종의 장미과 식물의 꽃차의 향기 성분 특성을 구명코자 꽃차를 headspace vial에 담은 후 solid phase microextraction(SPME)를 이용하여 추출한 후 gas chromatography-mass spectrometry를 이용하여 휘발성 성분을 분리하였다. 분리된 각 성분은 deconvolution 과정을 수행한 후 NIST masss spectral library를 이용하여 동정하였다. 매화꽃차에서는 총 58개의 휘발성 성분이 검출되었는데, benzaldehye와 nonane, 그리고 phenylmethanol이 주요 구성 성분으로 검출된 전체 휘발성 성분의 각각 64.7%, 16.1% 및 4.7%를 차지하고 있었다. 장미 꽃차의 경우 검출된 35종 중 주요 구성 성분은 nonane과 2-phenylethanol, 그리고 phenylmethanol로서 각각 전체 성분 중 54.0%, 18.0% 및 4.6%를 구성하고 있었다. 해당화 꽃차의 경우는 장미 꽃차와 동일하게 2-phenylethanol(62.2%)과 nonane(20.1%)이 주요 성분으로 동정되었으며 이들 2 성분의 합이 전체 43개 휘발성 성분의 82.3%를 차지하는 것으로 나타났다. 본 연구에 사용된 매화, 장미, 해당화 등 장미과 식물 3종의 꽃차 모두에서 공통적으로 검출된 휘발성 성분은 앞서 각 꽃차 종류별 주요 성분으로 언급된 4종의 성분을 포함하여 19종이었으며 매화꽃차에서만 검출된 성분은 29종으로 장미꽃차(6종)와 해당화 꽃차(8종)보다 향기성분의 다양성이 높은 것으로 나타났다.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.4
• /
• pp.437-445
• /
• 2023

A space system refers to a network of sensors, ground systems, and space-craft operating in space. The security of space systems relies on information systems and networks that support the design, launch, and operation of space missions. Characteristics of space operations, including command and control (C2) between space-craft (including satellites) and ground communication, also depend on wireless frequency and communication channels. Attackers can potentially engage in malicious activities such as destruction, disruption, and degradation of systems, networks, communication channels, and space operations. These malicious cyber activities include sensor spoofing, system damage, denial of service attacks, jamming of unauthorized commands, and injection of malicious code. Such activities ultimately lead to a decrease in the lifespan and functionality of space systems, and may result in damage to space-craft and, lead to loss of control. The Cybersecurity Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK) matrix, proposed by Massachusetts Institute of Technology Research and Engineering (MITRE), consists of the following stages: Reconnaissance, Resource Development, Initial Access, Execution, Persistence, Privilege Escalation, Defense Evasion, Credential Access, Discovery, Lateral Movement, Collection, Command & Control, Exfiltration, and Impact. This paper identifies cybersecurity activities in space systems and satellite navigation systems through the National Institute of Standards and Technology (NIST)'s standard documents, former U.S. President Trump's executive orders, and presents risk management activities. This paper also explores cybersecurity's tactics attack techniques within the context of space systems (space-craft) by referencing the Sparta ATT&CK Matrix. In this paper, security threats in space systems analyzed, focusing on the cybersecurity attack tactics, techniques, and countermeasures of space-craft presented by Space Attack Research and Tactic Analysis (SPARTA). Through this study, cybersecurity attack tactics, techniques, and countermeasures existing in space-craft are identified, and an understanding of the direction of application in the design and implementation of safe small satellites is provided.

• Parasites, Hosts and Diseases
• /
• v.61 no.4
• /
• pp.405-417
• /
• 2023

Chagas disease, caused by Trypanosoma cruzi parasite, is a significant but neglected tropical public health issue in Latin America due to the diversity of its genotypes and pathogenic profiles. This complexity is compounded by the adverse effects of current treatments, underscoring the need for new therapeutic options that employ medicinal plant extracts without negative side effects. Our research aimed to evaluate the trypanocidal activity of Bidens pilosa fractions against epimastigote and trypomastigote stages of T. cruzi, specifically targeting the Brener and Nuevo León strains-the latter isolated from Triatoma gerstaeckeri in General Terán, Nuevo León, México. We processed the plant's aerial parts (stems, leaves, and flowers) to obtain a methanolic extract (Bp-mOH) and fractions with varying solvent polarities. These preparations inhibited more than 90% of growth at concentrations as low as 800 ㎍/ml for both parasite stages. The median lethal concentration (LC₅₀) values for the Bp-mOH extract and its fractions were below 500 ㎍/ml. Tests for cytotoxicity using Artemia salina and Vero cells and hemolytic activity assays for the extract and its fractions yielded negative results. The methanol fraction (BPFC3MOH1) exhibited superior inhibitory activity. Its functional groups, identified as phenols, enols, alkaloids, carbohydrates, and proteins, include compounds such as 2-hydroxy-3-methylbenzaldehyde (50.9%), pentadecyl prop-2-enoate (22.1%), and linalool (15.4%). Eight compounds were identified, with a match confirmed by the National Institute of Standards and Technology (NIST-MS) software through mass spectrometry analysis.

• Journal of Food Hygiene and Safety
• /
• v.31 no.5
• /
• pp.327-334
• /
• 2016

This study was conducted to establish the standard method for the contents of biotin in milk formulas. To optimize the method, we compared several conditions for liquid extraction, purification and instrumental measurement using spiked samples and certified reference material (NIST SRM 1849a) as test materials. LC-MS/MS method for biotin was established using $C_{18}$ column and binary gradient 0.1% formic acid/acetonitrile, 0.1% formic acid/water mobile phase is applied for biotin. Product-ion traces at m/z 245.1 ${\rightarrow}$ 227.1, 166.1 are used for quantitative analysis of biotin. The linearity was over $R^2=0.999$ in range of $5{\sim}60{\mu}g/L$. For purification, chloroform was used as a solvent for eliminating lipids in milk formula. The linearity was over 0.999 in range of 5~60 ng/mL. The detection limit and quantification limit were 0.10, 0.31 ng/mL. The accuracy and precision of LC-MS/MS method using CRM were 103%, 2.5% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested milk formulas were acceptable contents of biotin compared with component specification and standards for nutrition labeling. The standard operating procedures were prepared for biotin to provide experimental information and to strengthen the management of nutrient in milk formula.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.17 no.1
• /
• pp.69-73
• /
• 2011

Unlike land fires, Fires on board a ship are not likely to be extinguished by skilled human resources using a variety of fire fighting equipments, but have to be brought under control on board a ship itself despite of difficult task. There are more cases of deaths from suffocation by smoke than from an increased temperature by heat in fires on board ships, because crew fail to secure a sufficient visibility range enough to escape from the scene of a fire or to leave the ship as early as possible. On the assumption that the height of ship's accommodation area increases from 2.0m to 2.3m comparable to the height of apartments on the ground in Korea, behaviors of fire smokes between the cases of 2.0m and 2.3m heights were compared and analyzed. Based on the blue print of the existing Training Ship "Hanbada", a new blueprint with the 30 cm height adjustment was additionally created. FDS (Fire Dynamic Simulator), which was created by the NIST in the United States and is the most widely distributed simulator for fires, was used to conduct a simulation and predict results. The results of simulation on the basis of temperature of $60^{\circ}C$ showed a safe evacuation period of time at the position 10m apart from the scene of a fire to increase by 55.8 seconds, when the height of ship's accommodation area increased from 2.0m to 2.3m. The results of simulation on the basis of visibility range of 6m showed the safe evacuation periods of time at the positions 10m, 20m and 30m apart from the scene of a fire to increase by 27.1 seconds, 109.2 seconds and 73.3 seconds, respectively, as the height of ship's accommodation area increased from 2.0m to 2.3m. This means that crew can escape more safely from a scene of fires on board when the height of ship's accommodation area is increased and equal to the height of living room in a building on land.

• Journal of Food Hygiene and Safety
• /
• v.32 no.5
• /
• pp.411-417
• /
• 2017

This study was conducted to establish the analysis method for the contents of choline in infant formulas and follow-up formulas by ion chromatograph (IC). To optimize the method, we compared several conditions for extraction, purification and instrumental measurement using spiked samples and certified reference material (CRM; NIST SRM 1849a) as test materials. IC method for choline was established using Ion Pac CG column and 18 mM $H_2SO_4$ mobile phase. The parameters of validation were specificity, linearity, LOD, LOQ, recovery, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity, $R_2$ was over 0.999 in range of 0.5~10 mg/L. The detection limit and quantification limit were 0.14, 0.43 mg/L. The accuracy and precision of this method using CRM were 95%, 2.1% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested products were acceptable contents of choline compared with component specification for nutrition labeling. The standard operating procedures were prepared for choline to provide experimental information and to strengthen the management of nutrient in infant formula and follow-up formula.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.11
• /
• pp.634-640
• /
• 2017

Toxicity and fate assessment is necessary in the evaluation of the environmental, health and safety risks of engineered nanomaaterials (ENMs). Therefore, in order to ensure the reproducibility, reliability and relevance of ENMs toxicity results, stable and monomodal dispersion protocols in toxicity test media are needed. Zinc oxide nanoparticles (nZnO) are widely used in various products such as cosmetic products, paper, paints etc. In this study, nZnO dispersions in ecotoxicity test media were produced by following a series of steps of modified National Institute of Standards and Technology (NIST) Special publication 1200-5. In addition, natural organic matter (humic acid (HA)) was used as a stabilizing agent to disperse nZnO in the test media. The hydrodynamic diameters (HDD) of the nZnO in dispersion ranged between 150 and 200 nm according to the dynamic light scattering (DLS) measurement. Based on these dispersions in ecotoxicity test using ecological species (Oryzias latipes, Daphnia magna, Pseudokirchneriella subcapitata and Chironomusus riparius), dispersion protocol was found to have a considerable potential in ecotoxicity test of ENMs.