• Geophysics and Geophysical Exploration
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• v.1 no.2
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• pp.127-135
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• 1998

The Born approximation is widely used for solving the complex scattering problems in electromagnetics. Approximating total internal electric field by the background field is reasonable for small material contrasts as long as scatterer is not too large and the frequency is not too high. However in many geophysical applications, moderate and high conductivity contrasts cause both real and imaginary part of internal electric field to differ greatly from background. In the extended Born approximation, which can improve the accuracy of Born approximation dramatically, the total electric field in the integral over the scattering volume is approximated by the background electric field projected to a depolarization tensor. The finite difference and elements methods are usually used in EM scattering problems with a 2D model and a 3D source, due to their capability for simulating complex subsurface conductivity distributions. The price paid for a 3D source is that many wavenumber domain solutions and their inverse Fourier transform must be computed. In these differential equation methods, all the area including homogeneous region should be discretized, which increases the number of nodes and matrix size. Therefore, the differential equation methods need a lot of computing time and large memory. In this study, EM modeling program for a 2D model and a 3D source is developed, which is based on the extended Born approximation. The solution is very fast and stable. Using the program, crosshole EM responses with a vertical magnetic dipole source are obtained and the results are compared with those of 3D integral equation solutions. The agreement between the integral equation solution and extended Born approximation is remarkable within the entire frequency range, but degrades with the increase of conductivity contrast between anomalous body and background medium. The extended Born approximation is accurate in the case conductivity contrast is lower than 1:10. Therefore, the location and conductivity of the anomalous body can be estimated effectively by the extended Born approximation although the quantitative estimate of conductivity is difficult for the case conductivity contrast is too high.

• Journal of Life Science
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• v.23 no.5
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• pp.609-615
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• 2013

Glyceollin I has gained attention as a useful therapy for various dermatological diseases. However, the binding property of glyceollin I to the mammalian adenylyl cyclase (hereafter mAC), a critical target enzyme for the down-regulation of skin melanogenesis, has not been fully explored. To clarify the action mechanism between glyceollin I and mAC, we first investigated the molecular docking property of glyceollin I to mAC and compared with that of SQ22,536, a well-known mAC inhibitor, to mAC. Glyceollin I showed superiority by forming three hydrogen bonds with Asp 1018, Trp 1020, and Asn 1025, which exist in the catalytic site of mAC. However, SQ22,536 formed only two hydrogen bonds with Asp 1018 and Asn 1025. Secondly, we confirmed that glyceollin I effectively inhibits the formation of forskolin-induced cAMP and the phosphorylation of PKA from a cell-based assay. Long term treatment with glyceollin I had little effect on the cell viability. The findings of the present study also suggest that glyceollin I may be extended to be used as an effective inhibitor of hyperpigmentation.

• Journal of Wetlands Research
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• v.5 no.2
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• pp.15-32
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• 2003

The ecological study on seven wetlands of Haman area in Kyungsangnamdo, Korea, was carried out. In especial, the biological data of the sites were unknown. In this study, water quality including water temperature, pH, DO, COD, T-N, T-P, SS were tested. On the survey of plants and animals, vegetation and flora were investigated and the fauna of insects, fish, and amphibians were studied on each wetland. Water of wetland Oksu was heavily polluted and wetlands Pyungy and Dodulyangy were relatively clean. The water pollution was most severe in winter at all of the wetlands. Plant communities were classified into 9 natural communities and 1 artificial community. On the vegetation, wetland Sugok showed the highest plant taxa, and 41 families, 78 species and 16 varieties were classified. There was remarkable difference in number of plant taxa. The difference may be caused by the variances of wetland sizes, the influence from terrestrial environment. Wetland Sugok showed most rich insect fauna, and 10 orders, 76 families 224 species and 1082 individuals were identified. The species diversity was 2.05 and the species richness was 73.49. Wetland Ddun showed poor insect fauna, and 6 orders, 23 families, 29 species and 81 individuals were identified. Total collected fish were 4 orders, 7 families and 11 species. The fish fauna was most rich in wetlands Oksu and Pyungy, but poor in wetland Unan. Total collected amphibians were 2 orders, 3 families and 4 species.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.2
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• pp.149-160
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• 2007

KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ${\sim}2.6\;t\;C\;ha^{-1}y^{-1}$. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric $CO_2$. The catchment scale water budget indicated that $30\sim40%$ of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about $12{\mu}mol\;CO_2/mmol\;H_2O$ with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.183-190
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• 2007

The site effects of seismic stations were evaluated by conducting a simultaneous inversion of the stochastic point-source ground-motion model (STGM model; Boore, 2003) parameters based on the accumulated dataset of horizontal shear-wave Fourier spectra. A model parameter $K_0$ and frequency-dependent site amplification function A(f) were used to express the site effects. Once after a H/V ratio of the Fourier spectra was used as an initial estimate of A(f) for the inversion, the final A(f) which is considered to be the result of combined effect of the crustal amplification and loca lsite effects was calculated by averaging the log residuals at the site from the inversion and adding the mean log residual to the H/V ratio. The seismic stations were classified into five classes according to $logA_{1-10}^{max}$(f), the maximum level of the site amplification function in the range of 1 Hz < f < 10 Hz, i.e., A: $logA_{1-10}^{max}$(f) < 0.2, B: 0.2 $\leq$ $logA_{1-10}^{max}$(f) < 0.4, C: 0.4 $\leq$ $logA_{1-10}^{max}$(f) < 0.6, D: 0.6 $\leq$ $logA_{1-10}^{max}$(f) < 0.8, E: 0.8 $\leq$ $logA_{1-10}^{max}$(f). Implication of the classified result was supported by observing a shift of the dominant frequency of average A(f) for each classified stations as the class changes. Change of site classes after moving seismic stations to a better site condition was successfully described by the result of the station classification. In addition, the observed PGA (Peak Ground Acceleration)-values for two recent moderate earthquakes were well classified according to the proposed station classes.

• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.191-202
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• 2007

To identify the detailed attenuation structure in the southern Korean Peninsula, a numerical test was conducted for the Q tomography inversion to be applied to the accumulated dataset until 2005. In particular, the stochastic pointsource ground-motion model (STGM model; Boore, 2003) was adopted for the 2D Q tomography inversion for direct application to simulating the strong ground-motion. Simultaneous inversion of the STGM model parameters with a regional single Q model was performed to evaluate the source and site effects which were necessary to generate an artificial dataset for the numerical test. The artificial dataset consists of simulated Fourier spectra that resemble the real data in the magnitude-distance-frequency-error distribution except replacement of the regional single Q model with a checkerboard type of high and low values of laterally varying Q models. The total number of Q blocks used for the checkerboard test was 75 (grid size of $35{\times}44km^2$ for Q blocks); Q functional form of $Q_0f^{\eta}$ ($Q_0$=100 or 500, 0.0 < ${\eta}$ < 1.0) was assigned to each Q block for the checkerboard test. The checkerboard test has been implemented in three steps. At the first step, the initial values of Q-values for 75 blocks were estimated. At the second step, the site amplification function was estimated by using the initial guess of A(f) which is the mean site amplification functions (Yun and Suh, 2007) for the site class. The last step is to invert the tomographic Q-values of 75 blocks based on the results of the first and second steps. As a result of the checkerboard test, it was demonstrated that Q-values could be robustly estimated by using the 2D Q tomography inversion method even in the presence of perturbed source and site effects from the true input model.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.223-243
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• 1989

The practical application of modern space science and technology have resulted in many actual and potential gains of mankind. These successes have conditioned and increased the need for a viable space law regime and the challenge of space has ultimately led to the formation of an international legal regime for space. Space law is no longer a primitive law. It is a modern law. Yet, in its stages of growth, it has not reached the condition of perfection. Therefore, under the existing state of thing, we could carefully say that the space law is one of the most newest fields of jurisprudence despite the fact that no one has so far defined it perfectly. However, if space law can be a true jurisprudential entity, it must be definable. In defining the space law, first of all, the grasp of it's nature iis inevitable. Although space law encompasses many tenets and facets of other legal discriplines, its principal nature is public international law, because space law affects and effects law relating intercourse among nations. Since early 1960s when mankind was first able to flight and stay in outer space, the necessity to control and administrate the space activities of human beings has growingly increased. The leading law-formulating agency to this purpose is the United Nation's ad hoc Committee on Peaceful Uses of Outer Space("COPUOS"). COPUOS gave direction to public international space law by establishing the 1963 Declaration of Legal Principles Governing the Activities of the States in the Exploration and Use of Outer Space("1963 Declaration"). The 1963 Declaration is very foundation of the five international multilateral treaties that were established successively after the 1963 Declaration. The five treaties are as follows: 1) The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space including Moon and other Celestial Bodies, 1967. 2) The Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of Objects Launched into Outer Space, 1968. 3) The Convention on International Liability for Damage Caused by Space Objects, 1972. 4) The Convention on Registration of Objects Launched into Outer Space, 1974. 5) The Agreement Governing Activities of States on the Moon and Other Celestial Bodies: Moon Treaty, 1979. The other face of space law is it's commercial aspect. Space is no longer the sole domination of governments. Many private enterprise have already moved directly or indirectly into space activities in the parts such as telecommunications and space manufacturing. Since space law as the public international law has already advanced in accordance with the developments of space science and technology, there left only a few areas untouched in this field of law. Therefore the possibility of rapid growth of space law is expected in the parts of commerical space law, as it is, at this time, in a nascent state. The resources of the space environment are also commercially both valuable and important since the resources include the tangible natural resources to be found on the moon and other celestial bodies. Other space-based resources are solar energy, geostationary and geosynchronous orbital positions, radio frequencies, area possibly suited to human habitations, all areas and materials lending themselves to scientific research and inquiry. Remote sensing, space manufacturing and space transportation services are also another potential areas in which commercial. endeavors of Mankind can be carried out. In this regard, space insurance is also one of the most important devices allowing mankind to proceed with commercial space venture. Thus, knowlege of how space insurance came into existence and what it covers is necessary to understand the legal issues peculiar to space law. As a conclusion the writer emphasized the international cooperation of all nations in space activities of mankind, because space commerce, by its nature, will give rise many legal issues of international scope and concern. Important national and world-community interests would be served over time through the acceptance of new international agreements relating to remote sencing, direct television broadcasting, the use of nuclear power sources in space, the regularization of the activities of space transportation systems. standards respecting contamination and pollution, and a practical boundary between outer space and air space. If space activity regulation does not move beyond the national level, the peaceful exploration of space for all mankind will not be realized. For the efficient regulation on private and governmental space activities, the creation of an international space agency, similar to the International Civil Aviation Organization but modified to meet the needs of space technology, will be required. But prior to creation of an international organization, it will be necessary to establish, at national level, the Office of Air and Space Bureau, which will administrate liscence liscence application process, safety review and sale of launch equipment, and will carry out launch service.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.47-85
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• 1989

The Fundamental purpose of the Warsaw Convention was to establish uniform rules applicable to international air transportation. The emphasis on the benefits of uniformity was considered important in the beginning and continues to be important to the present. If the desire for uniformity is indeed the mortar which holds the Warsaw system together then it should be possible to agree on a worldwide liability limit. This liability limit would not be so unreasonable, that it would be impossible for nations to adhere to it. It would preclude any national supplemental compensation plan or Montreal Agreement type of requirement in any jurisdiction. The differentiation of liability limits by national requirement seems to be what is occurring. There is a plethora of mandated limits and Montreal Agreement type 'voluntary' limits. It is becoming difficult to find more than a few major States where an unmodified Warsaw Convention or Hague Protocol limitation is still in effect. If this is the real world in the 1980's, then let the treaty so reflect it. Upon reviewing the Warsaw Convention, its history and the several attempts to amend it, strengths become apparent. Hijackings of international flights have given rise to a number of lawsuits by passengers to recover damages for injuries suffered. This comment is concerned with the liability of an airline for injuries to its passengers resulting from aviation terrorism. In addition, analysis is focused on current airline security measures, particularly the pre-boarding screening system, and the duty of air carriers to prevent weapons from penetrating that system. An airline has a duty to exercise a high degree of care to protect its passengers from the threat of aviation terrorism. This duty would seemingly require the airline to exercise a high degree of care to prevent any passenger from smuggling a weapon or explosive device aboard its aircraft. In the case an unarmed hijacker who boards having no instrument in his possession with which to promote the hoax, a plaintiff-passenger would be hard-pressed to show that the airline was negligent in screening the hijacker prior to boarding. In light of the airline's duty to exercise a high degree of care to provide for the safety of all the passengers on board, an acquiescene to a hijacker's demands on the part of the air carrier could constitute a breach of duty only when it is clearly shown that the carrier's employees knew or plainly should have known that the hijacker was unarmed. A finding of willful misconduct on the part of an air carrier, which is a prerequisite to imposing unlimited liability, remains a question to be determined by a jury using the definition or standard of willful misconduct prevailing in the jurisdiction of the forum court. Through the willful misconduct provision of the Warsaw Convention, air carrier face the possibility of unlimited liability for failure to implement proper preventive precautions against terrorist. Courts, therefore, should broadly construe the willful misconduct provision of the Warsaw Convention in order to find unlimited liability for passenger injuries whenever air carrier security precautions are lacking. In this way, the courts can help ensure air carrier safety and prevention against terrorist attack. Air carriers, therefore, would have an incentive to increase, impose and maintain security precautions designed to thwart such potential terrorist attacks as in the case of Korean Air Lines Flight No.858 incident having a tremendous impact on the civil aviation community. The crash of a commercial airliner, with the attending tragic loss of life and massive destruction of property, always gives rise to shock and indignation. The general opinion is that the legal system could be sufficient, provided that the political will is there to use and apply it effectively. All agreed that the main responsibility for security has to be borne by the governments. I would like to remind all passengers that every discovery of the human spirit may be used for opposite ends; thus, aircraft can be used for air travel but also as targets of terrorism. A state that supports aviation terrorism is responsible for violation of International Aviation Law. Generally speaking, terrorism is a violation of international law. It violates the soverign rights of the states, and the human rights of the individuals. I think that aviation terrorism as becoming an ever more serious issue, has to be solved by internationally agreed and closely co-ordinated measures. We have to contribute more to the creation of a general consensus amongst all states about the need to combat the threat of aviation terrorism.

• The Korean Journal of Air & Space Law and Policy
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• v.25 no.1
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• pp.3-26
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• 2010

The European Union(EU) has recently introduced its Directive 2008/101/EC to include aviation in the EU ETS(emissions trading system). As an amendment to Directive 2003/87/EC that regulates reduction of the green house gas(GHG) emissions in Europe in preparation for the Kyoto Protocol, 1997, it obliges both EU and non-EU airline operators to reduce the emission of the carbon dioxide(CO2) significantly in the year 2012 and thereafter from the level they made in 2004 to 2006. Emission allowances allowed free of charge for each airline operator is 97% in the first year 2012 and 95% from 2013 and thereafter from the average annual emissions during historical years 2004 to 2006. Taking into account the rapid growth of air traffic, i.e. 5% in recent years, airlines operating to EU have to reduce their emissions by about 30% in order to meet the requirements of the EU Directive, if not buy the emissions right in the emissions trading market. However, buying quantity is limited to 15% in the year 2012 subject to possible increase from the year 2013. Apart from the hard burden of the airline operators, in particular of those from non-European countries, which is not concern of this paper, the EU Directive has certain legal problems. First, while the Kyoto Protocol of universal application is binding on the Annex I countries of the Climate Change Convention, i.e. developed countries including all Member States of the European Union to reduce GHG at least by 5% in the implementation period from 2008 to 2012 over the 1990 level, non-Annex I countries which are not bound by the Kyoto Protocol see their airlines subjected to aircraft emissions reductions scheme of EU when operating to EU. This is against the provisions of the Kyoto Protocol dealing with the emissions of GHG including CO2, target of the EU Directive. While the Kyoto Protocol mandates ICAO to set up a worldwide scheme for aircraft emissions to contribute to stabilizing GHG concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system, the EU ETS was drawn up outside the framework of the international Civil Aviation Organization(ICAO). Second, EU Directive 2008/101 defines 'aviation activities' as covering 'flights which depart from or arrive in the territory of a Member State to which the [EU] Treaty applies'. While the EU airlines are certainly subject to the EU regulations, obliging non-EU airlines to reduce their emissions even if the emissions are produced during the flight over the high seas and the airspace of the third countries is problematic. The point is whether the EU Directive can be legally applied to extra-territorial behavior of non-EU entities. Third, the EU Directive prescribes 2012 as the first year for implementation. However, the year 2012 is the last year of implementation of the Kyoto Protocol for Annex I countries including members of EU to reduce GHG including the emissions of CO2 coming out from domestic airlines operation. Consequently, EU airlines were already on the reduction scheme of CO2 emissions as long as their domestic operations are concerned from 2008 until the year 2012. But with the implementation of Directive 2008/101 from 2012 for all the airlines, regardless of the status of the country Annex I or not where they are registered, the EU airlines are no longer at the disadvantage compared with the airlines of non-Annex I countries. This unexpected premium for the EU airlines may result in a derogation of the Kyoto Protocol at least for the year 2012. Lastly, as a conclusion, the author shed light briefly on how the Korean aviation authorities are dealing with the EU restrictive measures.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.137-172
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• 2008

The earliest safety data programs, the FDR and CVR, were electronic reporting systems that generate data "automatically." The FDR program, originally instituted in 1958, had no publicly available restrictions for protections against sanctions by the FAA or an airline, although there are agreements and union contracts forbidding the use of FDR data for FAA enforcement actions. This FDR program still has the least formalized protections. With the advent of the CVR program in 1966, the precursor to the current FAR 91.25 was already in place, having been promulgated in 1964. It stated that the FAA would not use CVR data for enforcement actions. In 1982, Congress began restricting the disclosure of the CVR tape and transcripts. Congress added further clarification of the availability of discovery in civil litigation in 1994. Thus, the CVR data have more definitive protections in place than do FDR data. The ASRS was the first non-automatic reporting system; and built into its original design in 1975 was a promise of limited protection from enforcement sanctions. That promise was further codified in an FAR in 1979. As with the CVR, from its inception, the ASRS had some protections built in for the person who might have had a safety problem. However, the program did not (and to this day does not) explicitly deal with issues of use by airlines, litigants, or the public media, although it appears that airlines will either take a non-punitive stance if an ASRS report is filed, or the airline may ignore the fact that it has been filed at all. The FAA worked with several U.S. airlines in the early 1990s on developing ASAP programs, and the FAA issued an Advisory Circular about the program in 1997. From its inception, the ASAP program contained some FAA enforcement protections and company discipline protections, although some protection against litigation disclosure and public disclosure was not added until 2003, when FAA Order 8000.82 was promulgated, placing the program under the protections of FAR 193, which had been added in 2001. The FOQA program, when it was first instituted through a demonstration program in 1995, did not contain protections against sanctions. Now, however, the FAA cannot take enforcement action based on FOQA safety data, and an airline is limited to "corrective action" under the program. Union contracts can exclude FOQA from the realm of disciplinary action, although airline practice may be for airlines to require retraining if there is no contract in place forbidding it. The data is protected against disclosure for litigation and public media purposes by FAA Order 8000.81, issued in 2003, which placed FOQA under the protections of FAR 193. The figure on the next page shows when each program began, and when each statute, regulation, or order became effective for that program.