• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.3
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• pp.103-111
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• 2016

Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

• Journal of the Korean GEO-environmental Society
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• v.16 no.7
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• pp.5-13
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• 2015

The pressure penetrating steel pipe pile method which can be constructed in a narrow space using the hydraulic jack is used on the foundation reinforcement, extension of the structure and basement, restoration of the differential settlement etc.. This method is possible to construct in narrow areas and low story height, the non-noise and non-vibration works, and it is possible for the construction site to be clean without slime. And it is possible to confirm the bearing capacity of pile due to penetrating the pile with the compression load of hydraulic jack. In this study, the static load test with the load-transfer test was carried out to investigate the bearing behavior characteristics of the pressure penetrating steel pipe pile. Four series of static load test were executed to investigate the variation of bearing behavior of the pressure penetrating steel pipe pile. As a result of these tests, the allowable load of the pressure penetrating steel pipe was evaluated more than 637 kN, and the shaft resistance corresponding to 81~86% of each applied load was mobilized with only a small portion of the base resistance acting. And it was also evaluated that the unit skin friction was mobilized to maximum value after two months.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.596-608
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• 2018

As urban infrastructure is aging, the possibility of accidents due to the failures or breakdowns of infrastructure increases. Especially, aging underground infrastructures like sewer pipes, waterworks, and subway have a potential to cause an urban ground sink. Urban ground sink is defined just as a local and erratic collapse occurred by underground cavity due to soil erosion or soil loss, which is separated from a sinkhole in soluble bedrock such as limestone. The conventional measurements such as differential settlement gauge, inclinometer or earth pressure gauge have a shortcoming just to provide point measurements with short coverage. Therefore, these methods are not adequate for monitoring of an erratic subsidence caused by underground cavity due to soil erosion or soil loss which occurring at unspecified time and location. Therefore, an alternative technology is required to detect a change of underground physical condition in real time. In this study, the feasibility of a novel magnetic resonance based monitoring method is investigated through laboratory tests, where the changes of path loss (S21) were measured under various testing conditions: media including air, water, and soil, resonant frequency, impedance, and distances between transmitter (TX) and receiver (RX). Theoretically, the transfer characteristic of magnetic field is known to be independent of the density of the medium. However, the results of the test showed the meaningful differences in the path loss (S21) under the different conditions of medium. And it is found that the reflection coefficient showed the more distinct differences over the testing conditions than the path loss. In particular, input reflection coefficient (S11) is more distinguishable than output reflection coefficient (S22).

• Tunnel and Underground Space
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• v.28 no.6
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• pp.635-650
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• 2018

Many people have been recognized that the Korean Peninsula is no longer safe area from the earthquake by the recent earthquakes occurred in the country. The earthquakes that occurred at Pohang and Gyeongju appeared differently from them considered in the seismic design and researches on the seismic design method have been also conducted by many researchers. Studies on seismic loads are mainly focused on existing superstructures, and research involving them has been actively carried out in reality. However, paper regarding structural stability of reinforcement from seismic load such as soil-nails, rock-bolts, ground anchors which were constructed to ensure stability of serviced structure have been published rarely. In this study, ground anchor been effected by static load and seismic load which is settled in the weathered rock is analyzed. Results for static load are obtained from field test and seismic load is from numerical analysis. In this study, the behavioral characteristics of the ground anchor were analyzed by numerical analysis in case of seismic loading based on the result of the in-situ tensile test of the ground anchor settled weathered rock. As a result, settlement of concrete block due to application of tension force for ground anchor occurred as well as following loss of axial force for ground anchor. Also, as bond length and period of seismic load are longer, increasement of displacement is greater.

• Journal of The Geomorphological Association of Korea
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• v.20 no.3
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• pp.15-25
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• 2013

The purpose of this study is to identify the environment of optimal location of the dwelling (hereafter referred as dwelling site) in the Neolithic Age found in Unseo-dong relics group, Yeongjong-do, Incheon from the geographical and geomorphological perspectives. For this purpose, micro-landform, altitude, gradient, distance from the river of water available for use and the difference between the highest altitude and lowest altitude of river bed of water available for use based on change of dwelling site over periods were analyzed targeting ground surface of hills where individual dwelling sites (a total of 68 sites) discovered in investigation area so far. As a result, it was shown that the Upper sideslope were selected as the primary dwelling location standard in investigation area where the Neolithic people lived upon selecting the dwelling site (or settlement). In addition, the ground surface of dwelling site had the altitude of 21-31m and slope of $5-10^{\circ}$ (gentle slope) as the secondary and it had distance of 514-549m from the river of water available for use and difference of 11-23m between the highest altitude and lowest altitude of river bed of water available for use. Thus, it was shown that the space to get water relatively easy from two places at the same time was the secondary dwelling location standard.

• Journal of recreation and landscape
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• v.6 no.2
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• pp.27-36
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• 2012

This study, presents the details of a propulsion system for a systematic approach to the remodeling of rural villages as part of the pilot project that will be implemented in 2013. Studies on remodeling rural villages have focused mainly on various concepts of remodeling purposes and functions, and on the size and allocation standards of the facilities, such as rural houses, village rest areas, or public facilities. Thus, research is required on the establishment of a plan to restructure rural spaces and suggestions regarding the standards applicable at the local sites. This study employed an upward access system to prepare for the remodeling project and encourage the local residents' participation. As a result, the local residents voluntarily participated in drawing up a comprehensive plan for the village maintenance settings and forms, and for making the arrangements, by discussing the pros and cons of the plan, or through the forum. Based on this result, the local government examined the project in terms of its specifics, size, timing, budgetary appropriation, and anticipated results in order to implement the project, and also provided aid from the field experts to review the plan for the space and facility plans, and the legal system to establish the remodeling plan for the rural villages. Thus, this study attempts to contribute toward improving the quality of the rural villager's lives through a comprehensive remodeling of the whole rural village, not through an individual remodeling method.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.453-467
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• 2016

Overall risks that can occur in a shield TBM tunnelling are studied in this paper. Both the potential risk events that may occur during tunnel construction and their causes are identified, and the causal relationship between causes and events is obtained in a systematic way. Risk impact analysis is performed for the potential risk events and ways to mitigate the risks are summarized. Literature surveys as well as interviews with experts were made for this purpose. The potential risk events are classified into eight categories: cuttability reduction, collapse of a tunnel face, ground surface settlement and upheaval, spurts of slurry on the ground, incapability of mucking and excavation, and water leakage. The causes of these risks are categorized into three areas: geological, design and construction management factors. Bayesian Networks (BN) were established to systematically assess a causal relationship between causes and events. The risk impact analysis was performed to evaluate a risk response level by adopting an Analytic Hierarchy Process (AHP) with the consideration of the downtime and cost of measures. Based on the result of the risk impact analysis, the risk events are divided into four risk response levels and these levels are verified by comparing with the actual occurrences of risk events. Measures to mitigate the potential risk events during the design and/or construction stages are also proposed. Result of this research will be of the help to the designers and contractors of TBM tunnelling projects in identifying the potential risks and for preparing a systematic risk management through the evaluation of the risk response level and the migration methods in the design and construction stage.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.855-867
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• 2018

When a weak zone exists ahead of tunnel face, the stress in the adjacent area would increase due to the longitudinal arching effect and the stability of the tunnel is affected. Therefore, it is critical to prepare a countermeasure through the investigation of the frontal weakness zone of the excavated face. Although there are several researches to predict the existence of weak zone ahead of tunnel face, such as geophysical exploration, numerical analysis and tunnel support, lack of studies on the relaxation zone depending on the width or distance from the vulnerable area. In this study, the impact of the weak zone on the formation of the relaxation zone was investigated. For this purpose, a series of laboratory test were carried out varying the width of the weak zone and the separation distance between tunnel face and weak zone. In the model test, sand with a water content of 3.8% was used to form a model ground. The model weak zone was constructed with dry sand curtains. The tunnel face was adjusted to allow a sequential excavation of upper and lower half part. load cells were installed on the bottom of the foundation and the tunnel face and measuring instruments for displacement were installed on the surface of the model ground to measure the vertical stress and surface displacements due to tunnel excavation respectively. The test results show that the width of weak zone did not affect the ground settlement while the ground subsidence drastically increased within 0.25D. The vertical stress and horizontal stress increased from 0.5D or less. In addition, the longitudinal arching effect is likely within the 1.0D zone ahead of the tunnel face, which may reduce the vertical stress in the ground following tunneling direction.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.279-310
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• 2015

The Montreal Convention is an agreement that governs the liability of air carriers for injury and death to passengers travelling internationally by air. The Montreal Convention serves as the exclusive legal framework for victims and survivors seeking compensation for injuries or death arising from accidents involving international air travel. The Montreal Convention sets monetary liability caps on damages in order to promote the financial stability of the international airline transport industry and protect the industry from exorbitant damages awards in courts that would inevitably bankrupt an airline. The Convention allows a litigant suing under the Convention to avoid the liability caps in instances where the airline's culpability for the injury or death is the direct result of negligence, another wrongful act, or an omission of the airline or its agents. The Montreal Convention identifies specific locations as appropriate venues to advance claims for litigants seeking compensation. These venues are closely tied to either the carrier's business operations or the passenger's domicile. In March 2015, in an act of suicide stemming from reactive depression, the co-pilot of Germanwings flight 9525 intentionally crashed the aircraft into the French Alps killing the passengers and the remaining crew. Subsequent to the crash, there were media reports that Lufthansa made varying settlement offers to families of the passengers who died aboard the flight ranging from $8,300 USD to $4.5 Million USD depending on the passengers' citizenship. The unverified offers by Lufthansa prompted outcries from the families of the decedent passengers that they would institute suit against the airline in a more plaintiff friendly jurisdiction such as the United States. The first part of this article accomplishes two goals. First, it examines the Montreal Convention's venue requirement along with an overview of the recoverable damages from countries comprising the citizenship of the passengers who were not American. The intentional crash of Germanwings flight 9525 by its First Officer encompasses the possibility that Lufthansa may be exposed to unlimited compensatory damages beyond the liability caps contained in the Convention. The second part of this article explores the application of the Convention's liability limits to the Germanwings flight to demonstrate that the likelihood of escaping the liability limits is slim.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.177-199
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• 2015

Commerce enriches human life enriched and within commerce, transportation of cargo is arguably the most important in business transactions. Traditionally, marine transport has been major commercial transaction, but carriage cargo by air is on the increase. While the fare for freight in comparison with that of ocean is higher, air freight has many benefits that justify the higher shipping fee; lower insurance premium, packing charges, inventory control, cost management and especially speed. Therefore, air freight transport is accumulating gradually. An air waybill(AWB) is needed in the air transport flow. It is a nonnegotiable security, so the holder cannot transfer of a right to a third party. Some scholars suggest that a negotiable AWB is needed. However, it seems nearly impossible to do so; an e-AWB use shows a gain in numbers, even if it has not met expectations. Going forward, it would appear reasonable to conduct a follow-up study on the utility and legal problem for e-AWB. After sending goods, the consignor has the right of disposition of cargo in some cases, and more research is necessary, because it is related to change of ownership and a trade settlement. According to WATS (World Airlines Transport Statistics), the Korean Air took third place in international freight in 2014, and fifth in total, domestic and international to great acclaim. However, there is a lack of research supporting the business showing. It is hope that more studies on e-AWB, stoppage in transit, and a risk of outstanding amount, etc. connect to develop Korean air freight industry.