• Journal of Veterinary Clinics
• /
• v.31 no.4
• /
• pp.282-287
• /
• 2014

The negative impacts of roads on wildlife mortality have been well documented, and one of the most significant impact is wildlife-vehicle collisions (WVCs) in most countries throughout the world. While road impacts on wildlife are a truly global concern with a large socio-economic cost, few researches in Korea have been quantified road-kill occurrence on highways or identified extensively seasonal and geographic patterns of this phenomenon. Therefore, we analyzed highway mortality of wild mammals in Korea using database from five years of nation-wide data on WVCs, and estimated road-kill density by standardizing on per km and per $10^3$ vehicle basis. During 2008 through 2012, a total of 10,940 wildlifes were reported killed on highways, with an average of 2,188 cases per year. There were 2,376 road-kills in 2012, and this equates to 0.01 road-kills per km per week or one road-kill every 88.5 km per week. For time of day, road-kills occurred more frequently in the early morning (05:00-08:00, 38.3%), and day of week did not have a significant influence in any individual year. The road-kill was highest in the spring (March- May, 33.0%) and least in the winter (December-February, 16.1%), and the most frequently killed native species were of Korean water deer (79.7%), raccoon dog (12.7%), Korean hare (3.1%), and leopard cat (1.2%). The overall standardized kill-rate (number/10 km/1,000 vehicles/month) in 2012 was 0.057 with highest on Dangjinyeongdeok highway (0.476), followed by Yeongdong (0.274), Sooncheonwanju (0.233), Iksanpohang (0.187), and Joongang (0.150). This study highlights that the frequency of WVCs are prevalent throughout the highways in Korea. Further work is needed to determine whether such a level of mortality is sustainable from an ecological point of view.

• Korean Journal of Agricultural Science
• /
• v.37 no.3
• /
• pp.435-449
• /
• 2010

Soils in the sloping uplands in Korea are subject to intensive land use with high input of agrochemicals and are vulnerable to soil erosion. Development of the environmentally sound land management strategy is essential for a sustainable production system in the sloping upland. This report addresses the status of upland agriculture and the best management practices for the uplands toward the sustainable agriculture. More than 60% of Korean lands are forest and only 21% are cultivating paddy and upland. Uplands are about 7% of the total lands and about 62% of the uplands are in the slopes higher than 7%. Due to the site-specificity of the upland, many managerial and environmental problems are occurring, such as severe erosion, shallow surface soils with rocky fragments, and loadings of non-point source (NPS) contaminants into the watershed. Based on the field trials, most of the sloping uplands were classified as Suitability Class III-V and the major limiting factor was slope and rock fragments. Due to this, soils were over-applied with N fertilizer, even though N rate was the recommendation. This resulted in decreases in yield, degradation of soil quality and increases in N loading to the leachate. Various case studies drew management practices toward sustainable production systems. The suggested BMP on the managerial, vegetative, and structural options were to practice buffer strips along the edges of fields and streams, winter cover crop, contour and mulching farming, detention weir, diversion drains, grassed waterway, and slope arrangement. With these options, conservation effects such as reductions in raindrop impact, flow velocity, runoff and sediment loss, and rill and gully erosion were observed. The proper management practice is a key element of the conservation of the soil and water in the sloping upland.

• Structural Engineering and Mechanics
• /
• v.57 no.3
• /
• pp.507-528
• /
• 2016

Reduced beam section (RBS) moment resisting connections are among the most economical and practical rigid steel connections developed in the aftermath of the 1994 Northridge and the 1995 Kobe earthquakes. Although the performance of RBS connection has been widely studied, this connection has not been subject to in the skewed conditions. In this study, the seismic performance of dogbone connection was investigated at different angles. The Commercial ABAQUS software was used to simulate the samples. The numerical results are first compared with experimental results to verify the accuracy. Nonlinear static analysis with von Mises yield criterion materials and the finite elements method were used to analyze the behavior of the samples The selected Hardening Strain of materials at cyclic loading and monotonic loading were kinematics and isotropic respectively The results show that in addition to reverse twisting of columns, change in beam angle relative to the central axis of the column has little impact on hysteresis response of samples. Any increase in the angle, leads to increased non-elastic resistance. As for Weak panel zone, with increase of the angle between the beam and the column, the initial submission will take place at a later time and at a larger rotation angle in the panel zone and this represents reduced amount of perpendicular force exerted on the column flange. In balanced and strong panel zones, with increase in the angle between the beam and the central axis of the column, the reduced beam section (RBS), reaches the failure limit faster and at a lower rotation angle. In connection of skewed beam, balanced panel zone, due to its good performance in disposition of plasticity process away from connection points and high energy absorption, is the best choice for panel zone. The ratio of maximum moment developed on the column was found to be within 0.84 to 1 plastic anchor point, which shows prevention of brittle fracture in connections.

• Journal of Forest and Environmental Science
• /
• v.34 no.4
• /
• pp.304-312
• /
• 2018

This study investigates to identify the impact factors of timber production cost on the relationship between production cost components and revenues generated by evaluating the entire timber supply chain. In this research, selected 13 logging zones as target areas and classified 14 forest production cost factors, six groups. Additionally, established 13 externalenvironmental factors with related stakeholders and forestry experts. And the BCR (Benefit Cost Ratio) method was then used to analyze the economics of each zone. Filled up a checklist and rated using 5 point scale for each target region, and extracted major cost factors for the production economy of the item. The analysis of major cost factors in the timber production revealed that wood grab equipment usage fee was the first ranked and forest trees purchase cost was ranked in the $2^{nd}$Also, the $3^{rd}$ranking was logging expenses, and transport cost, which accounted for 84% of the total cost, was ranked in the $4^{th}$. In addition, the rock land ratio, slope, timber payment (forest trees purchase cost), special timber, ratio of timber, DBH (Diameter at Breast Height), and mixed forest ratio were the factors that most affected the timber supply chain cost.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.10a
• /
• pp.189-195
• /
• 2000

New concept of LNG-FPSO ship with moonpool and bilge step in bottom is considered and investigated in the point of motion reduction and sloshing phenomena of the cargo and operation tanks. The cargo capacity of the ship of which principle dimensions is L x B x D x t(design) =270.0 x 51.0 x 32.32 x 13.7(m) 16K at 98% loading condition. The two moonpools and rectangular step at bilge part are setted up specially for getting the effect of motion decrease. For the motion analysis, linearized three dimensional diffraction theory with the simplified boundary conditions is used. The six-degree of freedom coupled motion responses are calculated for the LNG-FPSO ship. Viscous effects on the roll motion responses of a vessel are taken into account in this calculation program using an empirical formula suggested by Ikeda, Himeno and Tanaka is used. The case study for the moonpool size had been carried out by theoretical estimation and experimental method. For the optimization of the moonpool size and effect of the step, 9 cases of its size and with and without step are considered. From the results of calculation and experiment, it can be concluded that this designed LNG-FPSO ship have possibility to carry out her missions in the rough sea as for the owner's demand waves condition. The motion responses, especially roll motion, for the designed LNG-FPSO ship are much lower than those of another drillship and shuttle tanker and limit criterions are satisfied. For the check of the cargo tank and operation tank sizes we have performed sloshing analysis in the irregular waves which focuses on the pressure distribution on the tank wall and the time history of pressure and free surface for No.2 and No5. tanks of LNG-FPSO with chamfers. Finally we got the tank size which has no resonance and no impact pressure in all filling in the bow quartering and beam sea.

• Biomolecules & Therapeutics
• /
• v.20 no.1
• /
• pp.1-18
• /
• 2012

Schizophrenia is a devastating psychiatric illness that afflicts 1% of the population worldwide, resulting in substantial impact to patients, their families, and health care delivery systems. For many years, schizophrenia has been felt to be associated with dysregulated dopaminergic neurotransmission as a key feature of the pathophysiology of the illness. Although numerous studies point to dopaminergic abnormalities in schizophrenia, dopamine dysfunction cannot completely account for all of the symptoms seen in schizophrenia, and dopamine-based treatments are often inadequate and can be associated with serious side effects. More recently, converging lines of evidence have suggested that there are abnormalities of glutamate transmission in schizophrenia. Glutamatergic neurotransmission involves numerous molecules that facilitate glutamate release, receptor activation, glutamate reuptake, and other synaptic activities. Evidence for glutamatergic abnormalities in schizophrenia primarily has implicated the NMDA and AMPA subtypes of the glutamate receptor. The expression of these receptors and other molecules associated with glutamate neurotransmission has been systematically studied in the brain in schizophrenia. These studies have generally revealed region- and molecule-specifi c changes in glutamate receptor transcript and protein expression in this illness. Given that glutamatergic neurotransmission has been implicated in the pathophysiology of schizophrenia, recent drug development efforts have targeted the glutamate system. Much effort to date has focused on modulation of the NMDA receptor, although more recently other glutamate receptors and transporters have been the targets of drug development. These efforts have been promising thus far, and ongoing efforts to develop additional drugs that modulate glutamatergic neurotransmission are underway that may hold the potential for novel classes of more effective treatments for this serious psychiatric illness.

• Korean Journal of Construction Engineering and Management
• /
• v.14 no.5
• /
• pp.26-34
• /
• 2013

Recently, many companies recognize the individual human resource as a core asset of the corporate value creation and devote a lot of effort to develop and manage competency-based human resource in order to strengthen the corporate competitiveness. As the integrated construction company taking the major portion in Korean construction industry, its construction engineers perform the construction supervision task with various related parties at each stage of the life cycle of the construction project. Therefore, the competency of a construction engineer is an important factor which have a direct impact on the success of the construction project. However, the current capability evaluation scheme of the domestic construction engineers is mainly oriented on the qualification factors such as the certificates or the seniority and this is quite different from evaluating the actual ability for construction management tasks. In this point of view, this study proposes the appropriate level of proficiency in cost management by analyzing the work process and its detailed items of the cost management that is the one of the basic management items of the construction industry. Based on this, this study analyzes the current competency level of the construction engineer by comparing with the required competency of each job position and also performs the engineer's work competency analysis of each work step.

• Journal of the Economic Geographical Society of Korea
• /
• v.19 no.2
• /
• pp.209-224
• /
• 2016

The purpose of this study are to analyze the realities and characteristics of the inflow manufacturing factories located in non-urbanized area in the Capital region, and to extract the problems from locational point of view during the last 10 years. Using the raw data of factory registration statistics from 2006 to 2015, this study has intended to show the distributional characteristics of the independently-located manufacturing factories by various mapping methods. As a result, about 90% of the factories are heavily concentrated into 10 adjacent regions to Seoul and large cities. This study carried out questionaire surveys and in-depth interview to the leaders of Janganmyeon, Hwaseong-shi which have experienced the rapid increase of manufacturing factories. The independently-located factories have caused environmental pollution, destroyed rural village landscape, and affected the negative impact of the neighborhood community. The results of this study provide some implications to establish a desirable industrial location policy of non-urban areas in Capital region.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.3
• /
• pp.827-834
• /
• 2014

In order to meet the low voltage ride-through requirement in a grid code, a wind power plant (WPP) has to stay connected to a grid, supporting the voltage recovery for a grid fault. To do this, a plant-level controller as well as a wind generator (WG) controller is essential. The dynamic response of a WPP should be analyzed in order to design a plant-level controller. The dynamic response of a WPP for a grid fault is the collective response of all WGs, which depends on the wind speed approaching the WG. Thus, the dynamic response of a WPP should be analyzed by taking the wake effect into consideration, because different wind speeds at WGs will result in different responses of the WPP. This paper analyzes the response of a doubly fed induction generator (DFIG)-based offshore WPP with a grid fault taking into account the wake effect. To obtain the approaching wind speed of a WG in a WPP, we considered the cumulative impact of multiple shadowing and the effect of the wind direction. The voltage, reactive power, and active power at the point of common coupling of a 100 MW DFIG-based offshore WPP were analyzed during and after a grid fault under various wind and fault conditions using an EMTP-RV simulator. The results clearly demonstrate that not considering the wake effect leads to significantly different results, particularly for the reactive power and active power, which could potentially lead to incorrect conclusions and / or control schemes for a WPP.

• Korean Journal of Ecology and Environment
• /
• v.41 no.4
• /
• pp.541-546
• /
• 2008

The purpose of this study was to evaluate ecosystem health effect in the physiological levels, based on ethoxyresorufin-O-deethylase (EROD) and total oxyradical scavenging capacity (TOSC) assays using sentinel fish species. We collected fish samples of Zacco platypus in May 2008 from 3 sampling sites including upstream, midstream, and downstream of the Gap Stream. EROD activity was averaged 4.54 in the downstream, 2.7 fold higher than upstream and indicated that stream condition was degraded along with longitudinal gradient from up to downstream. Downstream, especially was significantly increased (p < 0.01) so that indicated various pollutants including nutrient enrichment and toxicant exposure from the point sources, wastewater treatment plant and industrial complex may impact to the stream condition. In the mean time, TOSC assays showed higher in the midstream than other sites, but the values were not significant, compared to the previous report on oxidative stress. Overall results indicated that our approaches applying two biomarkers can be effectively used for diagnosis of the physiological levels in an integrative stream health assessments and can be applied as useful pre-warning techniques as a biochemical alarm system of organic pollutions.