• The Korean Journal of Air & Space Law and Policy
• /
• v.27 no.1
• /
• pp.103-122
• /
• 2012

Nowadays, advanced countries and international community in which provide many services and profits due to rapid progress space science and technology whereas there is rising possibility of damage by collision of space object and increase of space debris. I will propose the concept and range of damage in the basis of review of space treaty and space liability convention as form of international order to fair and complete compensate to victim of accident and hazardous space activity. And, I will try to discuss possibility of compensation on personal damage and mental damage, scope of material damage, possibility of compensation about environmental contamination, issue of satellite data sending, place of damage, and so on. Also, I would like to propose establishment of space tribunal and regional cooperative agency.

• Journal of Biosystems Engineering
• /
• v.36 no.1
• /
• pp.33-39
• /
• 2011

An optical sensing approach based on diffuse reflectance has shown potential for rapid and reliable on-site estimation of soil properties. Important sensing ranges and the resulting regression models useful for soil property estimation have been reported. In this study, a similar approach was applied to investigate the potential of reflectance sensing in estimating soil properties for Korean paddy fields. Soil cores up to a 65-cm depth were collected from 42 paddy fields representing 14 distinct soil series that account for 74% of the total Korean paddy field area. These were analyzed in the laboratory for several important physical and chemical properties. Using air-dried, sieved soil samples, reflectance data were obtained from 350 to 2500 nm on a 3 nm sampling interval with a laboratory spectrometer. Calibrations were developed using partial least squares (PLS) regression, and wavelength bands important for estimating the measured soil properties were identified. PLS regression provided good estimations of Mg ($R^2$ = 0.80), Ca ($R^2$ = 0.77), and total C ($R^2$ = 0.92); fair estimations of pH, EC, $P_2O_5$, K, Na, sand, silt, and clay ($R^2$ = 0.59 to 0.72); and poor estimation of total N. Many wavelengths selected for estimation of the soil properties were identical or similar for multiple soil properties. More important wavelengths were selected in the visible-short NIR range (350-1000 nm) and the long NIR range (1800-2500 nm) than in the intermediate NIR range (1000-1800 nm). These results will be useful for design and application of in-situ close range sensors for paddy field soil properties.

• Analytical Science and Technology
• /
• v.13 no.1
• /
• pp.12-21
• /
• 2000

The PIGE (Proton Induced Gamma ray Emission) method was applied for the measurement of light elements Li ~ K. A test measurement has been performed for geological, biological, environmental and material samples by using a standard sample for each element. The measurement was performed for the two proton energies of 2.4 and 3.4 MeV, and 3.4 MeV was found to yield better result for multielemental analysis. The result shows a fair agreement within 15% for all elements with standard values. The detection limits of Li, B, F and Na are less than 100 ppm, while those of the other elements are from a few hundred ppm to a few percents.

• Ocean and Polar Research
• /
• v.40 no.4
• /
• pp.223-235
• /
• 2018

This study was carried out to investigate benthic sedimentary environments and benthic polychaetous communities on the coast of Ulsan, located on the southern East Sea of Korea. This survey was conducted at 15 stations, four times seasonally in January, April, July and October 2016. From the coast to the outer sea, surface sediments turned into fine grained sediments. There were complex coarse-grained sedimentary facies in various forms in the coastal zones while those with mud facies were found in the offshore zone. Organic matter content (LOI) and sulfide amount (AVS) recorded extremely high values, and increased from the coast to the outer sea, showing a similar trend to mud content with depth. The benthic polychaetous community revealed a mean density of $525ind./m^2$, and the total species number of species was 84. The major dominant polychaetous species were Magelona japonica, Lumbrineris longifolia and Heteromastus filiformis throughout the four seasons. Magelona japonica was concentrated predominantly in shallow coastal areas, but was present in all the regions of the survey area. Lumbrineris longifolia showed higher density in offshore regions more than 30 m deep, whereas H. filiformis showed higher density in coastal areas less than 30 m in depth. As a result of cluster analysis, the study area was divided into three ecological areas according to species composition, such as the northern coastal area between Ulsan PortOnsan Port, the southern area around Hoeya River and the outer sea area. Benthic environments in the study area, as determined by AMBI and BPI index, maintained a healthy condition in all four seasons with the AMBI at a level above GOOD and BPI at a level above FAIR. As organic matter accumulation continues to take place in the Ulsan coastal area, it is essential that detailed research activities continue to be carried out and ongoing monitoring be maintained.

• Journal of Aerospace System Engineering
• /
• v.17 no.4
• /
• pp.58-66
• /
• 2023

The latest global issues are the Space economy and low-orbit Space communication. 3GPP announced Release 17 standardization in June 2022, and in this regard, the United States prepared a strategy to enhance the competitiveness of the low-orbit 5G-NTN Space industry, and create an ecosystem at the national level in March 2023. Global smartphone semiconductor manufacturers have announced the development and verification results of standard-based chip technology, and satellite communication operators are launching low-orbit 5G-NTN Space communication services and rate products through convergence between terrestrial communication networks. This study diagnoses the current status of Korea's low-orbit 5G-NTN space communication ecosystem. We present our ecosystem creation strategy in terms of fair competition in the market, the service legal system, and the national R&D governance system.

• Journal of Forest and Environmental Science
• /
• v.32 no.2
• /
• pp.129-139
• /
• 2016

Study was conducted to investigate tree diversity and its population and regeneration status in homegardens of upper Assam, Northeast India through field study by quadrat method. A total of 154 tree species have been recorded from 135 studied homegardens under 109 genera 53 families. Most of these species (79%) are indigenous to our country, while the rest (21%) arealiens (naturalized and cultivated exotics) by origin. Tree species richness per homegarden varies greatly in different homegardens and is ranged from 5 to 52 tree species with a mean of 22 ($SE{\pm}0.58$). A. malaccensis is the most dominant tree species in the studied homegardens contributed 34% of the total tree density of the documented trees. The tree density is much higher with 4,259 individuals $ha^{-1}$ but, basal area ($36.32m^2ha^{-1}$) is very less. Based on the number of individuals present, very rare species is accounted for 10%, rare species 39%, common species 19%, dominants 14% and predominant species 18% in the present study. The population density of 154 tree species is 4,259 (individuals $ha^{-1}$) for adults (>3.18 cm DBH), 5,902 (individuals $ha^{-1}$) for saplings and 38,164 (individuals $ha^{-1}$) for seedlings. The density of seedlings>saplings>adults represents good regeneration status of tree species in studied homegardens. The population structure study showed that about 8% tree species have good regeneration status, 9% have fair regeneration status, 48% have poor regeneration status and 34% tree species have no regeneration. Study suggests that research and development action is needed to stimulate regeneration of those tree species which having high importance value indices but showing poor or no regeneration. Based on present observation, it can be conclude that homegarden can emerge as an effective means for both economic well-being and biodiversity conservation in upper Assam, Northeast India.

• Journal of Korean Physical Therapy Science
• /
• v.16 no.4
• /
• pp.49-57
• /
• 2009

Background: The purpose of this study was to assess the test-retest reliability of balance measurements in older adults using balance measurement system(Good Balance). Methods: The subjects consisted of 49 female and 20 male in community-dwelling older adults. This study used a repeated-measure design. Each subject completed all the different tests once and they were then repeated with 2 minutes in between. Repeated two-ways analysis of variance(ANOVA), representing two test times and both sexes, was calculated for each of the two dependent variables. Intraclass correlation coefficients(ICCs) were used to assess the test-retest reliability. Results: 1) There was not significant difference between test and retest for mediolateral sway speed and anterioposterior sway speed under conditions of normal standing with eyes open, normal standing with eyes closed and semitandem standing with eyes open. There was not significant difference between males and females for mediolateral sway speed and anterioposterior sway speed under conditions of normal standing with eyes open, normal standing with eyes closed and semitandem standing with eyes open. There were not the interaction effects between genders and test time under three conditions. 2) The reproducibility between test and retest was excellent for anterioposterior sway speed(ICC=.77) under condition of normal standing with eyes open, and for mediolateral sway speed(ICC=.76) and anterioposterior sway speed(ICC=.84) under condition of semitandem standing with eyes open. The reproducibility between test and retest was fair to good for mediolateral sway speed(ICC=.64) under condition of normal standing with eyes open, for mediolateral sway speed(ICC=.63) and anterioposterior sway speed(ICC=.75) under condition of normal standing with eyes closed. Conclusion: Balance tests in older adults using balance measurement system(Good Balance) demonstrated acceptable levels of reliability.

• Journal of Forest and Environmental Science
• /
• v.38 no.2
• /
• pp.90-101
• /
• 2022

The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F_3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.

• International Journal of Computer Science & Network Security
• /
• v.23 no.10
• /
• pp.147-156
• /
• 2023

Electronic voting machines (EVMs) are replacing research ballots due to the errors involved in the manual counting process and the lengthy time required to count the votes. Even though these digital recording electronic systems are advancements, they are vulnerable to tampering and electoral fraud. The suspected vulnerabilities in EVMs are the possibility of tampering with the EVM's memory chip or replacing it with a fake one, their simplicity, which allows them to be tampered with without requiring much skill, and the possibility of double voting. The vote data is shared among all network devices, and peer-to-peer verification is performed to ensure the vote data's authenticity. To successfully tamper with the system, all of the data stored in the nodes must be changed. This improves the proposed system's efficiency and dependability. Elections and voting are fundamental components of a democratic system. Various attempts have been made to make modern elections more flexible by utilizing digital technologies. The fundamental characteristics of free and fair elections are intractability, immutability, transparency, and the privacy of the actors involved. This corresponds to a few of the many characteristics of blockchain-like decentralized ownership, such as chain immutability, anonymity, and distributed ledger. This working research attempts to conduct a comparative analysis of various blockchain technologies in development and propose a 'Blockchain-based Electronic Voting System' solution by weighing these technologies based on the need for the proposed solution. The primary goal of this research is to present a robust blockchain-based election mechanism that is not only reliable but also adaptable to current needs.

• Journal of The Korean Association For Science Education
• /
• v.38 no.1
• /
• pp.87-96
• /
• 2018

In this study, the trend of research and practice of science education for students with special educational needs was discussed in consideration of the aim of science education. Since the 1980s 'science for all' has been suggested as an important goal of science education and it has been pursued in the National Curriculum of Korea with differentiated teaching and learning approach. The meaning of 'science for all' should be expanded to science education for all students including minorities. However, comparing to 'normal' students, there have been relatively little researches and practices for those who need special educational supports as to meet their special talents or as to meet their special mental or physical challenges. Especially, the efforts for handicapped students or students with special educational needs (SEN) have been deficient in comparison to that of talented or gifted students. In this study the authors introduced the history and procedures of a 'Science Fair of Hope' with SEN students as an example of practice of science education for all, and then described the change among pre-service science teachers' attitudes towards disability and inclusive education, so as to discuss the practice and significance of science education for all students including SEN students.