• International Journal of Highway Engineering
• /
• v.11 no.1
• /
• pp.117-126
• /
• 2009

Total number of recorded earthquakes in Korea is more than 2,000 of which 48 were catastrophic. The impacts from infrastructure damage due to an earthquake to production facilities and lifelines may spread across boundaries of several regions via import-export relationships and can bring serious economic impact to other regions. The economic impacts from unscheduled events stem not only from the damage and direct losses, but also from the indirect losses during the recovery and reconstruction periods. To recover and reconstruct the facilities and lifelines damaged by unexpected events through investment or government financial aid, both the direct and the indirect economic impacts from an event need to be measured in regional and interregional contexts. Direct economic impact is the direct change of production and demand due to the disruption of production facilities and lifelines from an unexpected event, and indirect economic impact is the change in other sectors due to inter-industry relationships. The purpose of the paper is to analyze various economic impacts of an earthquake, especially impacts on transportation networks in Korea. We collected spatial and economic data from Korea, and analyzed and estimated final demand loss and commodity flows from the unscheduled event.

• The Journal of Bigdata
• /
• v.8 no.1
• /
• pp.99-109
• /
• 2023

Recently, not only in Korea but also around the world, we have been experiencing constant disasters such as typhoons, wildfires, and heavy rains. The property damage caused by typhoons and heavy rain in South Korea alone has exceeded 1 trillion won. These disasters have resulted in significant loss of life and property damage, and the recovery process will also take a considerable amount of time. In addition, the government's contingency funds are insufficient for the current situation. To prevent and effectively respond to these issues, it is necessary to collect and analyze accurate data in real-time. However, delays and data loss can occur depending on the environment where the sensors are located, the status of the communication network, and the receiving servers. In this paper, we propose a two-stage hybrid situation analysis and prediction algorithm that can accurately analyze even in such communication network conditions. In the first step, data on river and stream levels are collected, filtered, and refined from diverse sensors of different types and stored in a bigdata. An AI rule-based inference algorithm is applied to analyze the crisis alert levels. If the rainfall exceeds a certain threshold, but it remains below the desired level of interest, the second step of deep learning image analysis is performed to determine the final crisis alert level.

• Korean journal of applied entomology
• /
• v.20 no.4 s.49
• /
• pp.217-222
• /
• 1981

As a primary study on the economic injury level of A. tokionis larval populations in tobacco fields, we carried out some experiments for the evaluation of sampling efficiency of 3 sampling methods (pit-fall traps of apple pomace and rice bran, and clover patches) for the larval population and the regressions between loss and infested larval density The $10\times10cm$ clover patch showed a better sampling efficiency $11.8\;to\;18.0\%$ than the others. The sampling efficiency of clover patch becomes higher when the plots did not have any green plants. The linear regression equation (Y=4.2+1.383x) between loss (Y:kg/10a) and infested larval density (X: no. of larvae/plot) which was obtained by substitution of damage ratio and corrected damage ratio fitted the observed data better than the one (Y=2.68X) obtained without substitioning.

• 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.

• Molecules and Cells
• /
• v.40 no.10
• /
• pp.773-786
• /
• 2017

The loss of green coloration via chlorophyll (Chl) degradation typically occurs during leaf senescence. To date, many Chl catabolic enzymes have been identified and shown to interact with light harvesting complex II to form a Chl degradation complex in senescing chloroplasts; this complex might metabolically channel phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show that an oshcar knockout mutant exhibits persistent green leaves during both dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar mutants exhibit severe cell death at the vegetative stage; this cell death largely occurs in a light intensity-dependent manner. In addition, 7-HMC a treatment led to the generation of singlet oxygen ($^1O_2$) in Arabidopsis and rice protoplasts in the light. Under herbicide-induced oxidative stress conditions, leaf necrosis was more severe in hcar plants than in wild type, and HCAR-overexpressing plants were more tolerant to reactive oxygen species than wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to Chl a in senescent leaves, HCAR may play a critical role in protecting plants from high light-induced damage by preventing the accumulation of 7-HMC a and Pheo a in developing and mature leaves at the vegetative stage.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.3
• /
• pp.347-351
• /
• 2023

Flying fish Cypselurus agoo roe is a popular food ingredient due to its abundant nutrition, unique texture, and flavor. It contains high levels of polyunsaturated fatty acids, protein, and minerals such as calcium, phosphorus, potassium, and vitamins (A, B₁, B₂, B₆, and niacin), making it a highly utilized food ingredient. Additionally, it is widely used as a raw material for food and cooking in several countries. After harvesting, flying fish roe is dried and transported to processing plants, where it performed a re-moisturizing process. However, the conventional re-moisturizing process is time-consuming and results in some loss of quality. Thus, this study investigates the conditions required for the re-moisturization of flying fish roe including the composition of the immersion solution, immersion time, and conditions that could minimize damage to the roe. The results suggest a reasonable composition of immersion solution to minimize damage to flying fish roe and the most appropriate immersion time for re-moisturization. These results may provide valuable insights for the industry to enhance the quality of re-moisturized flying fish roe, leading to an increase in its market value and demand.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.3
• /
• pp.359-367
• /
• 2020

Neurodegenerative disorders in the elderly are characterized by gradual loss of memory and cognitive function. Oxidative stress caused by reactive oxygen species is associated with progressive neuronal cell damage and death in Alzheimer's disease, one of the most common neurodegenerative disorders. An edible brown seaweed, Ecklonia cava, contains a variety of biologically active compounds such as phlorotannins. In this study, we comparatively evaluated the total phenolic content, antioxidant capacity, and neuroprotective effects of the phlorotannin-rich extract from E. cava (PEEC). The total phenolic content of PEEC and dieckol was 810.8 mg gallic acid equivalents (GAE)/g and 996.6 mg GAE/g, respectively. Antioxidant capacity of PEEC was 1,233.8 mg vitamin C equivalents (VCE)/g and 392.1 mg VCE/g determined using ABTS and DPPH assays, respectively, while those of dieckol were 2,238.4 mg VCE/g and 817.7 mg VCE/g. High-performance liquid chromatography results revealed 48.08 ± 0.67 mg dieckol/g of PEEC. PEEC had neuroprotective effects in pheochromocytoma (PC-12) and human neuroblastoma (SH-SY5Y) cells against H₂O₂- and AAPH-induced oxidative damage, partly due to reduced intracellular oxidative stress. PEEC treatment inhibited acetylcholinesterase and butyrylcholinesterase in a dose-dependent manner. Taken together, these findings suggest that PEEC is a good source of antioxidants and neuroprotective materials.

• Preventive Nutrition and Food Science
• /
• v.13 no.2
• /
• pp.90-94
• /
• 2008

The protective effect of chungkukjang from Sunchang province against oxidative stress was evaluated in the cellular system using LLC-$PK_1$ renal epithelial cells. The LLC-$PK_1$ cells showed decrease in cell viability and elevation in lipid peroxidation by the treatment with the generators of nitric oxide (NO) and superoxide anion ($O_2^-$) produced by sodium nitrouprusside and pyrogallol, respectively. However, the methanol extract of chungkukjang significantly inhibited cellular loss and lipid peroxidation in a dose-dependent manner; in particular K chungkukjang (KC) exerted the strongest protective effect. In addition, the protective effect of chungkukjang from 3-morpholinosydnonimine, as a source of peroxynitrite, with simultaneous generations of NO and $O_2^-$, was also studied. Treatment with chungkukjangs significantly preserved the cell viability and inhibited lipid peroxidation caused by SIN-1 with dose-dependence. The present study suggests that chungkukjang from Sunchang province, especially KC, would have protective potential from oxidative stress induced by free radicals under cellular oxidative damage.

• The Journal of the Korean dental association
• /
• v.47 no.4
• /
• pp.211-224
• /
• 2009

This retrospective study was to analyze the inferior alveolar nerve and lingual nerve damage after the removal of mandibular third molars. In this questionnaire study, the subjects chosen for this study were 2472 dentists who answered the questionnaire about numbness after the extraction of lower third molars. The data collected by E-mail and web site included the incidence of removal of the lower third molars, the incidence and the experience of numbness of the inferior alveolar nerve and lingual nerve, rate and duration of recovery, the influence in day life after the long-term sensory loss, the period and amount of the indemnity in the case of medical dispute. The results are summarized as follows. 1. The experience rate and the incidence rate of the inferior alveolar nerve numbness by oral surgeons in the past year were19.9% and 0.14%. Those of the lingual nerve by oral surgeon were 7.7% and 0.05%.2. The experience rate and the incidence rate of the inferior alveolar nerve numbness by the dentists except oral surgeons in the past year were 9.7% and 0.19%. Those of the lingual nerve by the dentists except oral surgeons were 5.5% and 0.11%.3. The recovery rate of the inferior alveolar nerve after 1 year and 2 years were 85.6% and 91.3%. The recovery rate of the lingual nerve after 1 year and 2 years were 84.8% and 89.3%.In conclusion, most of numbness may be recovered within 2 years. However the possibility of long term and persistent numbness should not be neglected. Therefore practitioner must inform the possibility of nerve injury and include this possibility in the consent forms.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.17 no.2
• /
• pp.153-159
• /
• 2007

Usually equal noise exposure is considered to cause symmetrical hearing loss, but some screening audiometries of employees who were exposed to noise showed asymmetry. Therefore, this study was carried out to evaluate the distribution of asymmetrical hearing loss and the difference of air conduction level between left and right ear at the different frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000 Hz). Study subjects were 326 male employees who had participated in the noise-specific health examination from May to October, 2002. They were evaluated by otoscopic examination, pure tone audiometry and tympanometry. In all frequencies, hearing threshold level of left ear was worse than right ear. The mean interaural threshold differences between two ears were 0.83 dB at 500 Hz, 1.18 dB at 2,000 Hz, 2.29 dB at 3,000 Hz, 2.18 dB at 4,000 Hz, and statistically significant (p<0.05). The hearing loss of left ear was greater than right ear in occupationally noise-exposed workers. It is believed that left ear was more susceptible to noise damage than right ear