• Korean Journal of Veterinary Service
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• v.35 no.1
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• pp.39-45
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• 2012

This survey aims to provide information on the pattern of distress in wild avian animals in Gangwon province. This survey is based on 315 wild avian which were rescued by the Kangwon University Wildlife Rescue Center. The data was collected at the Wildlife Animal Center from September 2007 to August 2010, and by analyzing the shape of the wild animals killed or injured, the center seeks an efficient and systematic way to manage such distress. There are 55 species found, in this study including 40 common kestrel, 34 eurasian eagles, 20 common buzzards, 20 collared scops owls, 19 oriental scops owls, 16 brown hawk owls and 160 others. These are the results of the survey: 129 (40.3%) of 315 avian birds were found between June and August. Many cases in that term were observed falling from the nest or losing their mother because of unskilled flight during the breeding season's flight practicing process. Between November and December, 64 individual (20.3%) were found, and it's the second largest number. The main reasons for these results were starvation and exhaustion from the winter migratory season. The results indicated that the main reason for avian distress came from the following: collision with architecture windows in 73 cases (23.2%), starvation and exhaustion in 63 cases (20.0%), collision with vehicles in 51 cases (16.2%), becoming orphaned in 69 cases (21.9%), trespassing into buildings occurred in 19 cases (6.0%), collision with electric wires in 18 cases (5.7%), poaching materials in 13 cases (4.1%), becoming entangled by fishing wire and other miscellaneous materials in 4 cases (1.3%), infection from parasites in 4 cases (1.3%), toxicosis from such toxins like agricultural chemicals in 1 case (0.3%). Overall, the purpose of this investigation was to analyze cases of avian distress in Korea's wildlife. This study used areas, seasons and causes to understand origins of these animals distress. So that it can be utilized for organized wild avian rescue and treatment.

• Smart Structures and Systems
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• v.16 no.3
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• pp.383-399
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• 2015

Today, as railways increase their capacity and speeds, it is more important than ever to be completely aware of the state of vehicles fleet's condition to ensure the highest quality and safety standards, as well as being able to maintain the costs as low as possible. Operation of a modern, dynamic and efficient railway demands a real time, accurate and reliable evaluation of the infrastructure assets, including signal networks and diagnostic systems able to acquire functional parameters. In the conventional system, measurement data are reliably collected using coaxial wires for communication between sensors and the repository. As sensors grow in size, the cost of the monitoring system can grow. Recently, auto-powered wireless sensor has been considered as an alternative tool for economical and accurate realization of structural health monitoring system, being provided by the following essential features: on-board micro-processor, sensing capability, wireless communication, auto-powered battery, and low cost. In this work, an original harvester device is designed to supply wireless sensor system battery using train bogie energy. Piezoelectric materials have in here considered due to their established ability to directly convert applied strain energy into usable electric energy and their relatively simple modelling into an integrated system. The mechanical and electrical properties of the system are studied according to the project specifications. The numerical formulation is implemented with in-house code using commercial software tool and then experimentally validated through a proof of concept setup using an excitation signal by a real application scenario.

• Journal of the Korean Magnetics Society
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• v.27 no.2
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• pp.49-53
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• 2017

Metamaterials composed of split cut wire (SCW) on grounded polyimide film substrate have been investigated for the aim of electromagnetic wave absorbers operated in THz frequency band. Reflection loss and current density distributions are numerically simulated with variations of the SCW geometries using the commercial software. The minimum reflection loss lower than -20 dB has been identified at 5.5~6.5 THz. The simulated resonance frequency and reflection loss can be explained on the basis of the circuit theory of an inductance-capacitance (L-C) resonator. Dual-band absorption can be obtained by arrangement of two SCWs of different length on the top layer of the grounded substrate, which is due to multiple magnetic resonances by scaling of SCWs. With increasing the side spacing between SCWs, a more enhanced absorption peak is observed at the first resonance frequency that is shifted to a lower frequency.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.48-53
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• 1998

The purpose of this study was to compare heavy metal concentrations in uncontaminated soil with those in soil influenced by industrial activities, and to investigate the relationship between change of heavy metal content and the kind of industry at the Iksan 1st Industrial Complex that has started since 1975. Soils sampled in 0-3㎝ and 3-6㎝ soil depth, respectively were analized for content of Cd, Cu, Ni, Pb and Zn. Change of heavy metal content in soil of the industrial complex were more accumulated 16 to 25% of Cd and Cu, 93% of Pb and Zn, respectively in samples compared with natural soil uncontaminated. But there was no different in Ni content between two soil. Distribution of Cd in soil layer of 0 to 3cm was the highest concentration of 5 ppm more at the textile industries, and then higher at the chemicals and the food processing industries. In 3 to 6㎝ soil layer Cd content was the highest concentration of 5 ppm more at the metal processing industries, and then higher at the textile industries. Cd accumulation in soil was different according to a kind of industry and soil depth. Cu content was the highest value of 400 ppm more in soil layer of 0 to 3cm at the manufacturing electric wires industry area and showed the accumulation phenomenon in soil layer 3 to 6cm at the ohmmeter, machines and electric wires industry area. Ni content was 35 ppm more in soil of the metal plating and processing industries regardless of soil sampling layer. Then it was 25 ppm more in soil of the building stones and semiconductor industries. Pb content was from 400 to 1000 ppm in soil of the chemicals and textiles industries regardless of soil sampling layer. Zn content was 1200 ppm more in soil of the chemicals and silk fabrics industries regardless of soil depth, and then lower in order to soil of leather processing${\le}$metal plating industries. In conclusion, changes of heavy metal kinds and content in soil of this industrial complex area were caused by the type or kinds of industrial activities. Changes of Pb and Zn content in soil were dominated at this area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.37-43
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• 2017

This review investigates the basic principle of physical interactions and failure mechanisms introduced in the materials and inner parts of semiconducting components under electromagnetic pulses (EMPs). The transfer process of EMPs at the semiconducting component level can be explained based on three layer structures (air, dielectric, and conductor layers). The theoretically absorbed energy can be predicted by the complex reflection coefficient. The main failure mechanisms of semiconductor components are also described based on the Joule heating energy generated by the coupling between materials and the applied EMPs. Breakdown of the P-N junction, burnout of the circuit pattern in the semiconductor chip, and damage to connecting wires between the lead frame and semiconducting chips can result from dielectric heating and eddy current loss due to electric and magnetic fields. To summarize, the EMPs transferred to the semiconductor components interact with the chip material in a semiconductor, and dipolar polarization and ionic conduction happen at the same time. Destruction of the P-N junction can result from excessive reverse voltage. Further EMP research at the semiconducting component level is needed to improve the reliability and susceptibility of electric and electronic systems.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.57-68
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• 2005

This study surveyed planting areas along streets in Gangwon-do to find out how to improve the planting and use of street trees and herbaceous plants. There were 301,491 trees of 41 species on the streets of Gangwon-do in 2004. The predominant species of street trees were Ginkgo biloba ($40\%$), Prunus spp. (Prunus yedoensis and Prunus sargentii) ($25\%$), Platanus occidentalis ($5\%$), followed by Betula platyphylla var. japonica, Zelkova serrata, Prunus armeniaca var. ansu, Acer palmatum, and Pinus thunbergii. Eighty-four herbaceous plant species were found in the Youngseo district (the southern area of Gangwon-do); the ratio of native species to exotic was 51:33. The predominant species were Cosmos bipinnatus, Petunia hybrida, Tagetes spp., Aster koraiensis, and Fagopyrum esculentum. Eighty-nine herbaceous plant species were found in the Youngdong district (the eastern area of Gangwon-do); the ratio of native species to exotic was 55:33. The predominant herbaceous plants were Aster koraiensis, Tagetes spp., Petunia hybrida, Rudbeckia bicolor, Cosmos bipinnatus, Salvia splendens, Brassica oleraceae var. acephala, Aquilegia buergeriana var. oxysepala, Coreopsis drummondii, Viola tricolor, and Dianthus superbus var. longicalycinus. Appropriate pruning adds to the aesthetic value of trees and prolongs their useful life; it also maintains good health and thereby reduces the need to control insects and diseases. Street trees had not been properly pruned due to the presence of power lines and a shortage of pruning information. The pruning was controlled by Korea Electric Power Company, which has no pruning information. Pruning must be maintained by a professional landscape company in order to maintain good shape, such as that which is done for bonsai. In order to improve the planting, use and maintenance of landscape plants in Gangwon-do, the following recommendations are made: street tree species should be diversified, suitable street trees should be selected for each space, native species should generally be used, trees should be appropriately pruned and properly fertilized, pests and diseases should be controlled, plantings should be done in multiple layers, spatial arrangements should be improved, larger trees should be planted, and drainage and underground electric wires should be considered when planting.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.28-33
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• 2016

Batteries are used for main power engine in the fields such as mobiles, electric vehicles and unmanned submarines, for starter and lamp driver in general automotive, for emergency electric source in ship. These days, lead-acid and the lithium ion batteries are increasingly used in the fields of the secondary battery, and the lead-acid battery has a low price and safety comparatively, The lithium ion battery has a high energy density, excellent output characteristics and long life, whereas it has the risk of explosion by reacting with moisture in the air. But Recently, due to the development of waterproof, fireproof, dustproof technology, lithium batteries are widely used, particularly, because their usages are getting wider enough to be used as a power source for hybrid ship and electric propulsion ship, it is necessary to manage more strictly. Hybrid ship has power supply units connected to the packets to produce more than 500kWh large power source, and therefore, A number of the communication modules and wires need to implement the wire inspection and monitor system(WIIMS) that allows monitoring server to transmit detecting voltage, current and temperature data, which is required for the management of the batteries. This paper implements a low price type wireless inspection and monitoring system(WILIMS) of the lithium ion battery for hybrid vessels using BLE wireless communication modules and power line modem( PLM), which have the advantages of low price, no electric lines compared to serial communication inspection systems(SCIS). There are state of charge(SOC), state of health(SOH) in inspection parts of batteries, and proposed system will be able to prevent safety accidents because it allows us to predict life time and make a preventive maintenance by checking them at regular intervals.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.28-34
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• 2018

The purpose of this study is to fabricate a sensor module to detect the resistive leakage current (Igr) in real time that occurs to low voltage electric lines and to verify its reliability. In the case of the developed sensor module, wires are inserted into the zero current transformer (ZCT) and current transformer (CT) in advance and then the branch line is connected to the circuit breaker. The measurement result of the resistance of the distribution panel equipped with the developed sensor module shows that the resistance is $0.151m{\Omega}$ between the R and R phases, $0.169m{\Omega}$ between the S and S phases, and $0.178m{\Omega}$ between the T and T phases, respectively. The insulation resistance measured at AC 500 V and 1,000 V is $0.08m{\Omega}$ between the R, S, T and N phases, respectively. Then, the insulation resistance measured at DC 500 V is $83.3G{\Omega}$ between the R, S, T and G terminal, respectively. In addition, the applied withstanding voltage is AC 220 V/380 V/440 V and it was found that characteristics between all phases are good. This study measured the standby power by installing the developed sensor module at the rear of the MCCB and switching the circuit breaker on sequentially. The standby power is 1.350 W when one circuit breaker is turned on, 1.690 W when 2 circuit breakers are turned on, and 4.371 W when 10 circuit breakers are turned on. This study also verified the reliability of the standby power of the distribution panel equipped with the developed sensor module using the Minitab Program (Minitab PGM). Since the analysis shows the statistical average of 1.34627 in the reliable range of normal distribution, standard deviation of 0.001874, AD of 0.554, and P value of 0.140, it is found that the distribution panel equipped with the developed sensor module has high reliability.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.65-74
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• 2021

In order to efficiently inspect rapidly increasing old tunnels in many well-developed countries, many inspection methodologies have been proposed using imaging equipment and image processing. However, most of the existing methodologies evaluated their performance on a clean concrete surface with a limited area where other objects do not exist. Therefore, this paper proposes a 6-step framework for tunnel crack detection deep learning model development. The proposed method is mainly based on negative sample (non-crack object) training and Cascade Mask R-CNN. The proposed framework consists of six steps: searching for cracks in images captured from real tunnels, labeling cracks in pixel level, training a deep learning model, collecting non-crack objects, retraining the deep learning model with the collected non-crack objects, and constructing final training dataset. To implement the proposed framework, Cascade Mask R-CNN, an instance segmentation model, was trained with 1561 general crack images and 206 non-crack images. In order to examine the applicability of the trained model to the real-world tunnel crack detection, field testing is conducted on tunnel spans with a length of about 200m where electric wires and lights are prevalent. In the experimental result, the trained model showed 99% precision and 92% recall, which shows the excellent field applicability of the proposed framework.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.4
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• pp.15-29
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• 2021

Urban green spaces offer a variety of benefits to living things and humans. However, existing green spaces have been reduced and fragmented due to urbanization, and there is a limit to creating new large green spaces in densely developed cities. Street trees have fewer restrictions on land use, which can be a measure to secure green areas in cities. In Korea, excessive pruning is being done on some street trees for reasons such as blocking of building signboards, contact with electric wires, and restrictions on sidewalk widths. Therefore, it is necessary to quantitatively understand the relationship between the benefits provided by street trees and their structures to come up with an efficient and systematic planning and management plan for urban street trees. In this study, we quantitatively analyzed the relationship between the thermal comfort improvement by the shades of street trees and the vertical structure, planting environment, and types of street trees. To calculate the thermal comfort felt by human body, we calculated UTCI (Universal Thermal Climate Index) of each street tree. For the vertical structure of street trees, we used Terrestrial LiDAR and the point clouds of street tree's crown was sliced vertically at 1m intervals. We conducted a multiple regression analysis on the thermal comfort improvement using the variables we obtained from fields. As a result, in the case of a street tree's vertical structure, the lager the volume of tree's crown located 3-4m (β=0.298, p<.05) and 6-7m (β=0.568, p<.001) above clear length, the better the cooling effect. In addition, the thermal comfort improvement was assessed to decrease as the DBH increased (β=-0.435, p<.001). In general, the crown diameter and DBH are positively correlated, with a cooling effect occurring as crown diameter increases. In this study, the opposite result was obtained due to the small number of trees measured, so additional research is needed by increasing the number of tree samples. In the case of the planting environment, the effect of improving thermal comfort was higher in the shaded area of trees planted to the south (β=-0.541, p<.001). Since unsystematic management of street trees can deteriorate the function of them, quantitative evaluations of the vertical structure of street trees are required, which can provide specific measures for planning and management of urban street trees with thermal comfort effect.