• Journal of the Korean Society of Marine Environment & Safety
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• 제20권6호
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• pp.677-684
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• 2014

In response to possible HNS (Hazardous and Noxious Substance) spill accident, HNS spill accident scenario and response scenario were developed. The accident area listed in scenarios is the coastal area of Busan, and scenario for possible accident in the designated area and strategies to respond the accident were developed, respectively. The scenario for accident was developed by designating HNS spill according to risk evaluation of HNS and analysis of HNS spill probability along the coastal area of Busan, and then estimating possible and potential impact from the accident. The scenario for response has been suggested as a systematical responding operations in order to effectively reduce the estimated impact from the accident. The possible HNS spill accident on the seas around Busan, has been designated by the spillage of 1,000ton of xylene due to collision accident in Gamcheon Port, and the possible impacts occurred by the accident has been simulated with the help of the atmospheric and oceanic dispersion model of xylene. In the responding scenario for the accident, a phased strategies regarding emergency rescue of peoples, protection and recovery of xylene, protective measures for the responders, and post management of the accident have been suggested.

• Journal of the Korean Geotechnical Society
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• 제23권11호
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• pp.77-85
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• 2007

This paper investigates the mechanical characteristics of composite geo-material which was developed to reuse both dredged soils and bottom ash. The composite geo-material used in this experiment consists of dredged soil taken from the construction site of Busan New Port, cement, air foam and bottom ash. Bottom ash is a by-product generated at the Samcheonpo thermal power plant. Several series of laboratory tests were performed to investigate behavior characteristics of composite gee-material, in particular the reinforcing effect by mixing bottom ash. The experimental results of composite geo-material indicated that the stress-strain relationship and the unconfined compressive strength are strongly influenced by mixing conditions. Especially it was observed that the compressive strength of composite geo-material increased with an increase in bottom ash content due to reinforcing effect by the bottom ash. Compressive strength of composite geo-material increased with the increase in curing time. The 28-day strength of composite geo-material is $1.7{\sim}1.8$ times higher than the 7-day strength. The moist unit weight strongly depended on air-foam content as well as bottom ash content added to the composite goo-material. In composite geo-material, secant modulus ($E_{50}$) also increased as its compressive strength increased due to the inclusion of bottom ash.

• Journal of Distribution Science
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• 제11권6호
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• pp.31-40
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• 2013

Purpose - The Northeast Asian Logistic Hub strategy was established to create a national competitive advantage in northeast Asia. Countries in this region are competing fiercely to become the central base distribution port as the volume of container shipping continues to increase due to the northeast Asian (especially Chinese) economic growth. The primary method by which shippers are improving their customer service and distribution is enhancing profits by minimizing call ports on the key route through strategic affiliations and the use of large vessels. Each nation is planning large-scale investments in the construction of sea ports that can accommodate large vessels. This paper proposes ways by which the logistical strategies of domestic corporations can keep pace with changes in government policy concerning the Northeast Asian Business Hub policy. It examines the logistics system in the Northeast Asian region, analyzes the government's Northeast Asian Business Hub policy, and suggests logistical strategies for domestic corporations through an analysis based on a questionnaire designed to grasp domestic firms' needs and goals. Research design, data and methodology - The purpose of this study is to determine how shipping companies establish partnerships with third-party logistics providers and draws out the implications of the results. The survey methods used were personal interviews and questionnaires distributed to a sample population through e-mail, fax, mail, and telephone. A total of 600 questionnaires were distributed, of which 165 were returned. Among these, ten were excluded due to insufficient content; ultimately, 155 were used for the sample. The statistical data collection process was analyzed through data coating and a statistical package program. Results - This study argues that greater flexibility in policies, administration, and systems will be needed to significantly improve established business practices. In this dissertation, we primarily identify that in order to become a center of northeast Asian logistics, Korea must adopt a new paradigm and abandon the existing systems that are based on the economic and social systems that have stemmed from bureaucracy, inflexibility, chauvinism, and equalitarianism. Flexible policies, administration, and systems will be necessary to improve business practices. Domestic corporations must establish a strategic logistics hub and related network while simultaneously pursuing value-added logistics businesses by increasing their manpower and building a logistics information system. This will strengthen their competitive edge and lead to system improvements. Conclusions - Domestic corporations must adopt a new paradigm and use more reasonable business laws, systems, and policies that are based on market-driven flexibility and transparency. Moreover, social norms and regulations should be established to help ensure political and social security. Korea must also develop a culture of tolerance for foreign companies. Finally, the paradigm defining the policy governing the development of the capital city and its satellite cities in this context must be changed.

• Water for future
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• 제29권2호
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• pp.249-260
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• 1996

There have been easily found a number of examples that misleading or unreasonable measuring data set of physical variables are often produced in the field and the laboratory. The primary reason is that the specific requirements of civil engineers are initially disregarded in designing the experimental apparatus. It results from a lack of mutual understanding and co-operating between the user group and the maker. Therefore, their fundamental knowledge and apprehension become indispensible in order to obtain measuring data with high confidence and good quality In this study it is shortly explained the basic structure and the operation system of the experimental equipments commonly used at the present. A simple measuring set is developed which is quite easy for a general civil engineer to design and operate without any other specialty of mostly electricity electronics. Based upon this requirement, one of data logger named PPDL8 is newly designed by making use of the parallel port in the personal computer, consisting of multi-channels able to measure 8 different point values simultaneously. It can also use many valuable sub-programs existing in PC because the user makes his own programs necessary for measurement, by himself. Of all things, it has a great advantage to increase the applicability of field measurements much larger when adopting the notebook computer to operate with small battery only. In addition this study gives, in fact, the excellent agreements of in-situ field variables by showing their measuring results of temperature, distance and turbidity.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제3권3호
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• pp.517-531
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• 1999

This paper presents the development of the 2-mode variable gain high power amplifier for a transmitter of INMARSAT-M operating at L-band(1626.5-1646.5 MHz). This SSPA(Solid State Power Amplifier) is amplified 42 dBm in high power mode and 36 dBm in low power mode for INMARSAT-M. The allowable error sets +1 dBm of an upper limit and -2 dBm of a lower limit, respectively. To simplify the fabrication process, the whole system is designed by two parts composed of a driving amplifier and a high power amplifier, The HP's MGA-64135 and Motorola's MRF-6401 are used for driving amplifier, and the ERICSSON's PTE-10114 and PTF-10021 are used the high power amplifier. The SSPA was fabricated by the circuits of RF, temperature compensation and 2-mode gain control circuit in aluminum housing. The gain control method was proposed by controlling the voltage for the 2-mode. In addition, It has been experimentally verified that the gain is controlled for single tone signal as well as two tone signals. The realized SSPA has 42 dB and 36 dB for small signal gain within 20 MHz bandwidth, and the VSWR of input and output port is less than 1.5:1 The minimum value of the 1 dB compression point gets 5 dBm for 2-mode variable gain high power amplifier. A typical two tone intermodulation point has 32.5 dBc maximum which is single carrier backed off 3 dB from 1 dB compression point. The maximum output power of 43 dBm was achieved at the 1636.5 MHz. These results reveal a high power of 20 Watt, which was the design target.the design target.

• Strategy21
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• 통권37호
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• pp.104-143
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• 2015

China's new grand strategy, the "One Belt, One Road Initiative" (also Belt Road Initiative, or BRI) has two primary components: Chinese President Xi Jinping announced the "Silk Road Economic Belt" in September 2013 during a visit to Kazakhstan, and the "21^st Century Maritime Silk Route Economic Belt" in a speech to the Indonesian parliament the following month. The BRI is intended to supply China with energy and new markets, and also to integrate the countries of Central Asia, the Association of Southeast Asia Nations (ASEAN), and the Indian Ocean Region - though not Northeast Asia - into the "Chinese Dream". The project will be supported by the Asian Infrastructure Investment Bank (AIIB), due to open in 2016 with 57 founding members from all around the world, and China has already promised US$ 50 billion in seed funding. China's vision includes networks of energy pipelines, railways, sea port facilities and logistics hubs; these will have obvious commercial benefits, but also huge geopolitical significance. China seems to have two distinct aims: externally, to restore its historical sphere of influence; and internally, to cope with income inequalities by creating middle-class jobs through enhanced trade and the broader development of its economy. In South Korea, opinion on the BRI is sharply polarized. Economic and industrial interests, including Korea Railroad Corporation (KORAIL), support South Korean involvement in the BRI and closer economic interactions with China. They see how the BRI fits nicely with President Park Geun-hye's Eurasia Initiative, and anticipate significant commercial benefits for South Korea from better connections to energy-rich Russia and the consumer markets of Europe and Central Asia. They welcome the prospect of reduced trade barriers between China and South Korea, and of improved transport infrastructure, and perceive the political risks as manageable. But some ardently pro-US pundits worry that the political risks of the BRI are too high. They cast doubt on the feasibility of implementing the BRI, and warn that although it has been portrayed primarily in economic terms, it actually reveals a crucial Chinese geopolitical strategy. They are fearful of China's growing regional dominance, and worried that the BRI is ultimately a means to supplant the prevailing US-led regional security structure and restore the Middle Kingdom order, with China as the only power that matters in the region. According to this view, once China has complete control of the regional logistics hubs and sea ports, this will severely limit the autonomy of China's neighbors, including South Korea, who will have to toe the Chinese line, both economically and politically, or risk their own peace and prosperity.

• Journal of the Korean Society of Marine Environment & Safety
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• 제20권2호
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• pp.247-258
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• 2014

To evaluate the influence of the external force components on the littoral currents in the Gusipo beach, Jeonbuk, West Coast of Korea where a wide tidal sand flat developed, a coupled hydrodynamic model considered real time tidal currents and wave-induced currents was constructed in which the EFDC for tides and tidal currents, the SWAN for waves and the SHORECIRC for wave-induced currents were used as the hindcasting models. A series of field observations for tides, tidal currents and incident waves were carried out and especially to observe the littoral currents in the tidal sand flat, the GPS mounted and light weight drogues were used. Also wind data were collected from the adjacent weather station. To analyze the littoral current components, the numerical drogue tracking results considered real time winds, tides and waves were compared with the field drogue data. The drift speed of numerical drogues was reproduced as the range of 68.0~105.2% compared with the field data and the velocity error of main direction component showed a good result as -16.7~10.0%. As a result, in the mild slope tidal flat including wide surf zone, the tides and winds were the major affection component of the littoral currents, on the other hand, the wave-induced currents seemed the minor component when the incident wave heights were relatively small.

• Korean Journal of Plant Resources
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• 제23권2호
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• pp.187-196
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• 2010

A total of 10 islands (Kumodo and Komundo in Yeosu City; Oinarodo in Goheung County; Chongsando, Soando, and Pogildo in Wando County; Chodo in Jindo County; Uido, Huksando, and Hongdo in Shinan County) were surveyed to confirm distribution of naturalized plants from June 2006 to December 2008. A total of 100 naturalized plants taxa from 25 families were recorded. The highest number of naturalized plant species (82 taxa) was recorded on Oinarodo, while the lowest number was recorded on Hongdo (42 taxa) and on Uido (34 taxa). A total of 26 naturalized species taxa (such as Dactylis glomerata, Lolium perenne, Bromus unioloides, Rumex obtusifolius, Chenopodium album, Phytolacca americana, Barbarea vulgaris, Lepidium apetalum, Robinia pseudo-acacia, Trifolium repens, Erigeron annuus, Erigeron canadensis, Senecio vulgaris, Xanthium strumarium) was recorded in all study areas. Distribution of naturalized plants were categorized into 7 habitat types based on ecological traits: afforested land, beach, port, and vacant land, road boundary, road cut and slope area, waste arable land, landfill area, and wetland. Systematic management is required to conserve unique landscape, species diversity, vegetation and ecosystem of Dadohae National Park. In order to manage the naturalized plants in Dadohae National Park, basic surveys are most needed to understand distribution and dispersal of naturalized plants communities based on ecological features of each habitat type.

• Journal of the Korean Geotechnical Society
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• 제35권7호
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• pp.15-27
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• 2019

The purpose of this study is to investigate the mechanism about damages occurring at quay wall and backfill in Youngilman Port during Pohang earthquake (M5.4) on November 15, 2017. In the field investigation, the horizontal displacement of the caisson occurred between 5 cm and 15 cm, and the settlement at backfill occurred higher than 10 cm. 2D-effective Stress Analysis was performed to clarify the mechanism for the damage. The input earthquake motion used acceleration ($3.25m/s^2$) measured at bedrock of Pohang habor. Based on a numerical analysis, it was found that the effective stress decreased due to the increase of excess pore pressure in the backfill ground and the horizontal displacement of the caisson occurred by about 14 cm, and the settlement occurred by about 3 cm. In backfill, the settlements occurred between 6 cm and 9 cm. This is similar to field investigation results. Also, it was found that the backfill soil was close to the Mohr-Coulomb failure line due to the cyclic loading from the effective stress path and the stress-strain behavior. It may be related to decreasing of bearing capacity induced by the reduction of effective stress caused by the increase of the excess pore water pressure.

• Journal of the Korean GEO-environmental Society
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• 제23권9호
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• pp.5-16
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• 2022

In recent years due to the development of urban and underground space, the number of ground disasters is increasing, and it is also leading to social problems. To solve the problem, a grouting method is generally used. However, the grouting method has material (grout) limitations in permeability, gelation properties and tensile resistance. Therefore, research on grout materials mixed with fibers is actively carried out to improve the problems. However, in the actual ground injection process, many difficulties have been faced causing the blockage of the inlet port and the injection tube. In this study, 'CNT-mixed grout material' was developed using CNT powder that can reinforce the tensile strength of soils. The uniaxial compressive and tensile strength tests were performed to obtain the optimal content and mechanical properties of the CNT Powder-mixed grout. It was found that the optimal CNT powder content is 0.5% that gives the average maximum strength. A one-dimensional injection test and the bulb formation test were carried out, and it was identified that the injection rate and bulb form could be controlled by pressure and mixing ratio. Field application of the CNT-Mixed grout is simulated using numerical analysis of slopes, foundations, and tunnels reinforced in several types. The positive effect of reducing plastic ranges and settlements was confirmed.