• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.711-717
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• 2006

In order to study gas hydrate, potential future energy resources, Korea Institute of Geoscience and Mineral Resources has conducted seismic reflection survey in the East Sea since 1997. one of evidence for presence of gas hydrate in seismic reflection data is a bottom simulating reflector (BSR). The BSR occurs at the interface between overlaying higher velocity, hydrate-bearing sediment and underlying lower velocity, free gas-bearing sediment. That is often characterized by large reflection coefficient and reflection polarity reverse to that of seafloor reflection. In order to apply depth migration to seismic reflection data. we need high performance computers and a parallelizing technique because of huge data volume and computation. Phase shift plus interpolation (PSPI) is a useful method for migration due to less computing time and computational efficiency. PSPI is intrinsically parallelizing characteristic in the frequency domain. We conducted conventional data processing for the gas hydrate data of the Ease Sea and then applied prestack depth migration using message-passing-interface PSPI (MPI_PSPI) that was parallelized by MPI local-area-multi-computer (MPI_LAM). Velocity model was made using the stack velocities after we had picked horizons on the stack image with in-house processing tool, Geobit. We could find the BSRs on the migrated stack section were about at SP 3555-4162 and two way travel time around 2,950 ms in time domain. In depth domain such BSRs appear at 6-17 km distance and 2.1 km depth from the seafloor. Since energy concentrated subsurface was well imaged we have to choose acquisition parameters suited for transmitting seismic energy to target area.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.50-55
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• 2000

The United States has had the superiority in the global trading market, and focused on the deregulation, decentralization, and often competitiveness. Also, it has adhered to pluralistic and uncoordinated systems for its various standard related activities. But with the WTO TBT entering into force late in 1990s, international standards have become more important in the global telecommunication market. So it has been recognized that the progressive standard activity would lead to keep the superiority of the nation in global telecommunication market. Specially, as the EU has been most active in building an agreed-upon technical standards among Its members, the US has faced with a serious problem that it has lack of agreed-upon infrastructure for standards. Hence, to keep the leadership in international telecommunications market, now it has been focusing on the national approach to standardization activities through the governmental support. For the implementation of above purposes, it amended 2 Acts. One is the Telecommunication Act of 1996. The other is NTTAA(National Technology Transfer and Advancement Art) of 1996, which was enacted according to the 1995 report "Standards, Conformity Assessment, and Trade into the 21 Century" by )TRC(National Research Council). In this paper, we analyse the US legal system in telecommunication standardization field including above arts and their Implementing plans. And we suggest the need for the active system of government in our telecommunication standardization.

• Korean Journal of Social Welfare
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• v.39
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• pp.290-321
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• 1999

This Study has two research interests: First, to give a new perspective in searching for the identifying features of social welfare studies in Korea where social welfare is recognized as an independent discipline through an examination of german research trends in social policy, where social policy is not recognized as an independent discipline, but as a field of study. The reasons of non-recognition of social policy studies as an independent discipline in Germany are value problems, vagueness of research objects, and the position of social welfare in relation to another social sciences. Second, to show the trends of german studies in social policy from diverse disciplines, i. e. sociology, political science, law, history, pedagogics etc. and the common points in these studies. The results of this study are as follows. First, the common feature of german Studies on the social policy from diverse disciplins is above all the interest in the improvement of Lebenslage, i. e. conditions of life. Second, the value problems in social sciences are not solved till now, but the interests in the improvement of Lebenslage don't mean studies of social policy must handle with values. The interests in the applicability of social policy don't mean values must be improved in the studies either. Third, the vagueness of the objects can be found also in other social sciences and is not unique in social policy studies. Fourth, the studies, which focuses on the improvement of Lebenslage and can contribute to construct theories such as raising the effectiveness of state intervention must be recognized as studies of social policy, even though they are written by social scientists from other disciplines. This means the theories of social policy to pursue are connected with theories of middle range, i. e. with lower degree of abstraction.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.7
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• pp.552-561
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• 2016

In this experimental study, the dynamic stability derivatives of a tailless lambda-shape UAV are estimated from time history data of aerodynamic moments measured from the internal balance while the test model is forced to oscillate at given frequencies and amplitudes. A 3-axis forced oscillation apparatus is designed to induce decoupled roll, yaw, pitch oscillations respectively. The results show that the roll damping derivatives remain stable at the entire range of angle of attack tested, whereas the pitch damping derivatives become unstable beyond $15^{\circ}$ angle of attack. The amplitude and frequency have little impact on roll damping derivatives while the smaller amplitude and frequency of oscillation improves the pitch stability. The yaw damping derivative values are fairly small as expected for a tailless configuration. The results indicate that the proposed methodology and test apparatus area valid for estimating the dynamic stability derivatives of a tailless UAV.

• International Commerce and Information Review
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• v.15 no.4
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• pp.267-286
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• 2013

The WCO Time Release Study (TRS) is a unique tool and method for measuring the actual performance of Customs activities. The ultimate aim of TRS is to improve the performance of the function being measured. To be more specific, TRS is used for identifying bottlenecks in the international supply chain and/or constraints affecting Customs release, assessing newly introduced and modified techniques, procedures, technologies and infrastructure, or administrative changes, establishing baseline trade facilitation performance measurement, identifying opportunities for trade facilitation improvements and estimating the country's approximate comparative position as a benchmark tool. The effective utilization methods of TRS for trade facilitation in Korea Customs Services are as follows ; Firstly, it is necessary to make every efforts to identify bottlenecks in border-related procedures and improve their procedures for continuous and more improved trade facilitation. Secondly, it is necessary to optimize and simplify export-related procedures using the TRS in exportation for efficiency of total international supply chain. Thirdly, it is necessary to make coordinated border management with main trading partners. Lastly, it is necessary to enhance Korea's international status to support underdeveloped countries in the field of trade procedures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.9
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• pp.1-8
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• 2010

A digital phase wrapping modulation (DPM) open-loop polar transmitter can be efficiently applied to a wideband orthogonal frequency division multiplexing (OFDM) communication system by converting in-phase and quadrature signals to envelope and phase signals and then employing the signal mapping process. This mapping process is very similar to quantization in a general communication system, and when taking into account the error that appears during mapping process, one can replace the coordinates rotation digital computer (CORDIC) algorithm in the coordinate conversion part with the Taylor series approximation method. In this paper, we investigate the application of the Taylor series approximation to the cartesian to polar coordinate conversion part of a DPM polar transmitter for wideband OFDM systems. The conventional approach relies on the CORDIC algorithm. To achieve efficient application, we perform computer simulation to measure mean square error (MSE) of the both approaches and find the minimum approximation order for the Taylor series approximation compatible to allowable error of the CORDIC algorithm in terms of hardware design. Furthermore, comparing the processing speeds of the both approaches in the implementation with FPGA reveals that the Taylor series approximation with lower order improves the processing speed in the coordinate conversion part.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.50-57
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• 2016

Pipeline is one of the most abundant components in petrochemical plant. It plays a critical role in transporting fluids. Some pipelines are thermally insulated by wrapping them with insulating materials to prevent the loss of energy. However, when corrosion begins under insulation, it cannot be easily seen without unwrapping the cover, and thus corrossion should be detected using a non-destructive ways such as ultrasound guided wave. In this paper, the piping where the CUI (Corrosion Under Insulation) which occurs in the insulation parts guided waves effectively the optimum condition which is theoretical for selected guided waves phase velocity dispersion curve and wave-structure. The results of this study are expected to be directly utilized for onsite inspection of pipeline's CUI in many petrochemical plants.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.220-225
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• 2020

Hair is made of proteins containing various amino acids. Ultraviolet (UV) radiation is believed to be responsible for the most damaging effects of sunlight, and also plays an important role in hair aging. The purpose of this study was to investigate the changes in morphological and chemical structures after ultraviolet B (UVB) irradiation of human hair. The UVB-irradiated hair showed characteristic morphological and structural changes, compared to those of the normal hair. The result from a scanning electron microscope (SEM) equipped with an energy dispersive X-ray diffractometer (EDX) showed that the scale of UV-irradiated hair appeared to be rough and the amount of oxygen element was higher than that of the normal hair. Fluorescence and three dimensional (3D) topographical images were obtained by a confocal laser scanning microscope (CLSM). In 3D images, the green emission intensity of normal hair was much higher than that of fluorescing UVB-irradiated hair. The intensity of green emission reflects the intrinsic fluorescence of hair protein. Also, a fluorescent imaging method using fluorescamine reagent was used to identify the free amino groups resulting from a peptide bond breakage in UVB-irradiated hair. Strong blue fluorescence of UVB-irradiated hair, which indicates a very high level of amino groups, was observed by CLSM. Therefore, the fluorescamine as an extrinsic fluorescence could provide a useful tool to identify the peptide bond breakage in UVB-irradiated hair. Infrared image mapping was also employed to assess the cross-sections of normal and UVB-irradiated specimens to examine the oxidation of disulfide bonds. The degree of peak areas with strong absorbance for the disulfide mono-oxide was spread from the outside to the inside of hair. The spectroscopic techniques used alone, or in combination, launch new possibilities in the field of hair cosmetics.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.310-319
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• 2018

Background: Research on next-generation sequencing (NGS)-based HLA typing is active. To resolve the phase ambiguity and long turn-around-time of conventional high resolution HLA typing, this study developed a NGS-based high resolution HLA typing method that can handle large-scale samples within an efficient testing time. Methods: For HLA NGS, the condition of nucleic acid extraction, library construction, PCR mechanism, and HLA typing with bioinformatics were developed. To confirm the accuracy of the NGS-based HLA typing method, the results of 192 samples HLA typed by SSOP and 28 samples typed by SBT compared to NGS-based HLA-A, -B and -DR typing. Results: DNA library construction through two-step PCR, NGS sequencing with MiSeq (Illumina Inc., San Diego, USA), and the data analysis platform were established. NGS-based HLA typing results were compatible with known HLA types from 220 blood samples. Conclusion: The NSG-based HLA typing method could handle large volume samples with high-throughput. Therefore, it would be useful for HLA typing of bone marrow donation volunteers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.610-616
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• 2021

This study is a literature review that analyzes the head of Ri election rules and regulations described in the village code, identifies problems, and proposes solutions for these problems. For data collection, a total of 146 village codes was collected from January 2019 to August 2019. The results showed people in most villages vote for the head of Ri according to democratic electoral processes. For system improvement, a one-person, one-vote system was proposed instead of a one-family, one-vote system in order to enhance gender equality and political rights. As for the appointment system, the following changes were proposed: First, candidate eligibility should be improved as only people who were born in that village are eligible; Second, the maximum age of candidacy for the head of Ri should be established as under 65 years old by considering physical ability in the event of disaster occurrences and physical activity required for running village businesses; Third, consecutive terms of the head of Ri when there is no successor should be limited in order to prevent indigenous forces from settling in the local community; and Fourth, education should be provided for building the head of Ri's stature in order to devote to promote public interest for village development.