• Bulletin of the Korean Chemical Society
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• v.19 no.8
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• pp.830-835
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• 1998

The characteristics of the ablation plume generated by 532 nm Nd: YAG laser irradiation of a Pb(Zr0.52Ti0.48)O3 (PZT) target have been investigated using a pulsed-field time-of-flight mass spectrometer (TOFMS). The relative abundance of O+, Ti+, Zr+, Pb+, TiO+, and ZrO+ ions has been measured and discussed. TiO+ and ZrO+ ions were also found to be particularly stable within the laser ablation plasma with respect to PbO+ species. The behavior of the temporal distributions of each ionic species was studied as a function of the delay time between the laser shot and the ion extraction pulse. The most probable velocity of each ablated ion is estimated to be Vmp=1.1-1.6x 105 cm/s at a laser fluence of 1.2 J/cm2, which is typically employed for the thin film deposition of PZT. The TOF distribution of Ti+ and Zr+ ions shows a trimodal distribution with one fast and two slow velocity components. The fast velocity component (6.8x 10' cm/s) appears to consist of directly ablated species via nonthermal process. The second component, originated from the thermal evaporation process, has a characteristic velocity of 1.4-1.6 x 105 cm/s. The slowest component (1.2 x 105 cm/s) is composed of a dissociation product formed from the corresponding oxide ion.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.76-87
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• 2019

The purpose of this study was to evaluate the performance of and to derive future maintenance-management measures of the constructed alternative habitat for the Kaloula borealis at the University of Seoul, examining the period between 2015-2017. The research was constructed in 2014 and in a $191m^2$ area. The performance evaluation was divided into maintaining the habitat of the target species, maintaining the population and reproduction rates of the target species, maintaining the habitat of the wild species, the resilience of natural ecosystems, and the harmony with the surrounding environment. In terms of maintaining the habitat of the target species, soil collected from the existing habitat of the Kaloula borealis and was the depth was increased to 30cm in the alternative habitat. An artificial water supply was required every year during the supporting the spawning and hatching of other amphibians along with the Kaloula borealis. The sources of water of the alternative habitat were both rain and tap water, as it cannot be maintained naturally. Additionally, the Kaloula borealis thrived because it inhabited the research site and the average temperature was $26.2^{\circ}C$ from April-June, which is when the Kaloula borealis spawns. In terms of maintaining the population and reproduction rates of the Kaloula borealis, they were evaluated to have stable rates of reproduction. In terms of maintaining the habitat of the wild species, studies on vegetation and the structure of the characteristics of prey or predators will be needed. Also, alien species, such as Humulus japonicus and Bidens frondosa needed to be removed to maintain the wetland ecosystem of the wild species. In the assessment of the resilience of the natural ecosystems, the mud was monitored, noting the changes in the depth of water, with steps taken to reduce the leakage of water. The mud collected from the Haneul Pond wetland, which is located around the research site was piled up. Also, partial mowing management and the inducement of a natural vegetation colony was required for vegetation management. It was also necessary to create porous spaces, such as old trees and tree branches to create a habitat with hiding places and feeding and spawning places for small organisms. In terms of the harmony with the surrounding environment, the following threat factors needed to be managed: amphibian roadkill by vehicles and pedestrians and artificial draining due to nearby user access. Based on the monitoring results, alternative habitat management measures presented the promoting various waterside structures, in which amphibians can spawn and hide in, managing the water environment consistently, managing the vegetation, focused on the habitat of the wild species, and managing the surrounding environment for the habitat. The creation of an alternative habitat should be managed through monitoring, reflecting the characteristics of the changes in the site. Also continuing efforts are also needed to improve the habitat of the target species.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.286-294
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• 2015

Temporal and spatial characteristics of cyanobacterial communities at the monitoring stations for Harmful Algal Bloom Alert System (HABAS) in Nakdong River and Lake Dukdong were investigated for two years (2013 to 2014). A total of 30 cyanobacterial species from 14 genera were found at the survey stations. Microcystis sp. showed maximum cell density in the total cyanobacterial community in August, 2014 at ND-2 and in September, 2013 at ND-3 station. Lynbya limnetica and Geitlerinema sp., non-target species for alert criteria showed maximum cell density at ND-1 (August, 2013) and Dam station of Lake Dukdong (September, 2014), respectively. Total cyanobacterial cell density and the relative abundance of four target genera (Microcystis, Anabaena, Aphanizomenon and Oscillatoria spp.) for alert criteria was relatively lower in the mesotrophic Lake Dukdong than at the eutrophic riverine stations of Nakdong River, indicating cyanobacterial density and the RA of target genera is affected by the trophic state of the monitoring stations. Simulating the alert system using phycocyanin concentration as an alert criterion resulted in the longer period of alert issued compared to the period of alert issued using the current criterion of harmful cyanobacterial cell density due to the influence of phycocyanin concentration from non-target cyanobacterial species.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.2
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• pp.41-55
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• 2005

In an effort to preserve biodiversity in increasingly fragmented green patches, Korea has been installing eco-corridors over or under some arterial or expressways. In a survey of 43 such eco-corridors installed up until the year 2003, some problems and issues were identified. Some selected overseas eco-corridors were also investigated to find implications for the improvements of future installations in Korea. Major findings are; - For most existing eco-corridors, target species are not specified and locations of the eco-corridors are not well considered, and consequently it is questionable if wildlifes are crossing them - Most of existing eco-corridors lack supporting facilities such as fences that guide wildlife to cross them and prevent them from running into the road - Planting on the eco-corridors is not sufficient, not diverse enough in species, and not very considerate of wildlife but designed and planted in a similar manner as in urban parks - Where target species are not well specified, the location, width, cross section, and other aspects of the eco-corridors can not be optimized - It is suggested that eco-corridors are planned at early stages of road planning so that the number and locations of eco-corridor(s) decided as necessary and even the alignment and design of roads consider the installation of eco-corridors in advance - Monitoring of wildlife crossings is needed for improved eco-corridor planning and design - Nationwide green network plan is desirable to be made first and eco-corridors fit into it.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.277-291
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• 2020

In order to understand characteristics on bycatch of Korean tuna purse seine fishery, especially operations associated with Fish Aggregating Device (FAD) in the Indian Ocean, we conducted analyses related to bycatch by school association type (unassociated school, FAD associated school and log associated school) using the data collected by scientific observers from 2016 to 2018. The FAD used by Korean tuna purse seine fishery in the Indian Ocean was a drifting FAD, which belongs to non-entangling FADs according to the category proposed by the International Seafood Sustainability Foundation (ISSF). The target species of Korean tuna purse seine fishery are skipjack, yellowfin and bigeye tunas, accounting for 99% of the total catch. The ratio of bycatch was 0.97% in total catch and the discard accounted for less than 1%, indicating that most catch was retained on board. In terms of bycatch ratio by school association type, it accounted for 0.12% for unassociated school, 1.09% for FAD associated school and 1.25% for log associated school. As for the catch proportion of shark species by school association type, it accounted for 0.01% for unassociated school, 0.11% for FAD associated school and 0.10% for log associated school, which showed that unassociated school type was the lowest to affect bycatch of non-target and shark species. Given the proportion of bycatch compositions, however, it is considered that FAD associated school of Korean tuna purse seine fishery has less caught bycatch species of non-target and shark, compared to other fleets operating in the Indian Ocean.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.3
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• pp.239-247
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• 2010

Species of fish such as striped beakperch, bluefin searobin and konoshiro gizzard shad are commercially very important due to their high demand in the Korean market. When estimating acoustically the abundance of stocks for these species, it is of crucial importance to know the target strength (TS) to the length dependence. In relation to these needs, the TS experiments were conducted on three different species in an acrylic salt water tank using two split-beam echo sounders of 70 and 120 kHz. The TS for these three species under the controlled condition was simultaneously measured with the swimming movement by a DVR system and analyzed as a function of fish length (L) and frequency (or wavelength $\lambda$). The equation of the form TS=a log (L)+b log ($\lambda$)+c was derived for their TS-length dependence. The best fit regression of TS on fork length for striped beakperch was estimated as TS=35.67 log (L, m) -15.67 log ($\lambda$, m) -46.69 ($r^2$=0.78). Furthermore, the best fit regression of TS on fork length for konoshiro gizzard shad was shown to be TS=25.85 log (L, m) -5.85 log ($\lambda$, m) -32.22 ($r^2$=0.51). The averaged TS for 12 bluefin searobins with a mean length of 24.36cm at 70 kHz was analyzed to be -41.55dB. In addition, the averaged tilt angle obtained simultaneously by a DVR system with TS measurements for 27 konoshiro gizzard shads swimming within an acrylic salt water tank was estimated at $-2.7^{\circ}$.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1154-1162
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• 2021

The transcriptional capacities of target genes are strongly influenced by promoters, whereas few studies have focused on the development of robust, high-performance and cross-species promoters for wide application in different bacteria. In this work, four novel promoters (P_k.rtufB, P_k.r1, P_k.r2, and P_k.r3) were predicted from Ketogulonicigenium robustum and their inconsistency in the -10 and -35 region nucleotide sequences indicated they were different promoters. Their activities were evaluated by using green fluorescent protein (gfp) as a reporter in different species of bacteria, including K. vulgare SPU B805, Pseudomonas putida KT2440, Paracoccus denitrificans PD1222, Bacillus licheniformis and Raoultella ornithinolytica, due to their importance in metabolic engineering. Our results showed that the four promoters had different activities, with P_k.r1 showing the strongest activity in almost all of the experimental bacteria. By comparison with the commonly used promoters of E. coli (tufB, lac, lacUV5), K. vulgare (Psdh, Psndh) and P. putida KT2440 (JE111411), the four promoters showed significant differences due to only 12.62% nucleotide similarities, and relatively higher ability in regulating target gene expression. Further validation experiments confirmed their ability in initiating the target minCD cassette because of the shape changes under the promoter regulation. The overexpression of sorbose dehydrogenase and cytochrome c551 by P_k.r1 and P_k.r2 resulted in a 22.75% enhancement of 2-KGA yield, indicating their potential for practical application in metabolic engineering. This study demonstrates an example of applying bioinformatics to find new biological components for gene operation and provides four novel promoters with broad suitability, which enriches the usable range of promoters to realize accurate regulation in different genetic backgrounds.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.1
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• pp.22-33
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• 2009

Ecological risk assessment(ERA), developed in Australia, can be used to estimate the risk of target, bycatch and protected species from the effects of fishing using limited data for stock assessment. In this study, we employed the ERA approach to estimate risks to tunas, billfishes, sharks, sea turtles and other species by the Korean tuna longline fishery in the Western and Central Pacific Ocean using productivity and susceptibility analyses of the ERA based on low(<1.30), medium(1.30-1.84) and high risk(>1.84). Albacore, bigeye, yellowfin, skipjack and bluefin tunas were generally evaluated in the medium risk. The susceptibility of tuna species, however, had higher risks than the productivity. Billfishes were also at medium risk, while sharks were at high risk by the tuna longline fishery. The risk of productivity was generally high, because most sharks caught by the tuna longline fishery have high longevities, i.e., over 10 years, including ovoviviparous species. Susceptibility, which is related with the selection of fishing gear, was also high, because the longline fishery has no gear modifications to prevent bycatch of protected species. Not only target tuna species were influenced by the tuna longline fishery in the Western and Central Pacific Ocean, but also nontarget species, such as pomfret, mackerels rays, sea turtle were done. Ecosystem-based fishery assessment tools, such as productivity and susceptibility analysis(PSA), have the ability to provide broad scientific advice to the policy makers and stakeholders.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.1-14
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• 2013

A species restoration plan requires a process where the first is to thoroughly study the target species, second is to provide them with an onsite reproduction and adaptation period, and finally, third is to release them to their natural habitat. This study focuses on the space planning for target species' successful onsite reproduction and adaptation. For the study, a site planning near Sobaeksan National Park was implemented with Red Fox's behavior and habitat characteristics in mind for its recovery, reproduction, and natural adaptation. During site selection and planning, the basic aim was to incorporate the existing site as much as possible thus reducing the impact on the environment from the recovery plan. In addition, for a stable recovery of the Red Fox population, the site was classified into three different areas : core area, buffer zone, and transition area. Then, the facilities that help Red Fox's reproduction and adaptation such as reproduction center, foraging site, adaptation training center were planned. Under the condition that the site will be off limit to the public, a limited number of paths for monitoring was provided. For the site's vegetation, the existing species were planted as much as possible with the addition of plants that the Red Fox consume. The facilities included as Red Fox's habitat were fox burrows for hiding and ecological ponds for drinking. From this study, the recovery of the endangered fox species is expected as well as the contribution to an effort to increase of awareness toward the biological resources in Korea through Nagoya protocol. Furthermore, it has the potential to change the public's attitude toward endangered species recovery projects through publicizing and providing experience to the national park visitors.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.23-43
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• 2020

The purpose of this paper is to create ecological values for urban rivers. For this, the paper looks into river bed structures and how nearby lands are used. This study was performed to set the specific sections for analysis through a field investigation of the infrastructure conditions, surrounding land use, and the inter habitat structure of Seongnaecheon(Stream). A total of 780 individuals from 31 species of wild birds appeared in Seongnaecheon(Stream). According to foraging guild's habitat, there were 9 species of water, 8 types of water edges, 5 types of crowns, 5 types of shrubs, 2 types of tree trunks, 2 types of birds of raptors, and 355 individuals of water, 243 shrubs, 90 crowns, 84 water edges and 5 raptors. Many water birds were observed at the site where the Seongnaecheon(Stream) sandy plains and wetland herbaceous area were developed and the open water was secured. Most of the forest birds appeared on levee slope connected with forest around and riverside with fewer facilities for use. The species diversity index of Shannon, the entire section of Seongnaecheon(Stream), was 2.2697 and the downstream ecological landscape conservation area of Seongnaecheon(Stream) was found to be useful as a habitat for wild birds in the city compared to other sections. Some sections of Seongnaecheon (Stream) had low species diversity index due to lack of green space and surrounding urbanization areas. In choosing target species, I researched the special features of the habitats and the habitation structure of wild birds in each zone. Regarding detailed plans, by classifying the breeding place & roosting site and the roosting site & shelter that took account of the inhabitation characteristics of the target species in different sections, this paper suggested the major plant species and multilayer planting structures. Moreover, this study proposed the development of habitats for water birds and forest birds along with the connection of the green network for improving the Eco-corridor linkage and inhabitation features in Seongnaecheon(Stream).