• KSCE Journal of Civil and Environmental Engineering Research
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• 제32권6D호
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• pp.679-686
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• 2012

KTX step 1 April 2004, after the opening, the second phase of the project was opened in November 2010. High-speed rail after the opening and continue to increase the demand of high-speed rail, Have the speed of competitive advantage compared too the means of transportation. The opening of these high-speed rail has led to changes of the move, the company's position, and the spatial structure of the population of reorganization, such as the social, economic, transportation. In this study, survey data using the High Speed Rail Station EMME/2 of the program to take advantage of the 2-Dimentional Blancing trip distribution to investigate the passage through the trip distribution by the estimation of the parameters of the model to estimate the distribution of the means of access and high-speed rail station to reproduce and Analysis of the results by means of access parameters (${\theta}$) autos 0.0395, buses 0.0390, subway 0.0650, taxi 0.0415, the frequency distribution (Trip Length Frequency Distribution: TLFD) were analyzed survey data value model with the results of comparing $R^2$ cars analysis and model values similar survey data 0.909 bus 0.923, subway 0.745 to 0.922, taxi, F test P value analysis is smaller than 0.05 at the 95% confidence level as a note that was judged to have been. Trip frequency distribution analysis, but in the future, set the unit to 5km-trip frequency distribution middle zone Units from small zone units (administrative district) segmentation research is needed, and can reflect the trip distance 0~5 km interval combined function to take advantage of the gravity model and the 3-Dimentional Blancing applied research is needed to be considered.

• Journal of Korean Society of Environmental Engineers
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• 제33권4호
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• pp.289-299
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• 2011

We studied the characteristics of pollutant concentrations in 9 streams that flow into Shihwa Lake in order to provide the scientific data for effective implementation of total pollution loads management system (TPLMS) of the Lake. Suspended solid (SS), chemical oxygen demand (COD), dissolved nutrients ($NO_2$, $NO_3$, $NH_4$, $PO_4$ and $SiO_2$), total phosphorus (TP) and total nitrogen (TN) in stream water from industrial complexes, urban and agricultural regions were determined. Pollutant concentrations in December were higher than that in other sampling periods. COD concentration from industrial complex region with average of 12.6 mg/L was 2 times higher those from urban region (6.6 mg/L) and agricultural region (5.9 mg/L). TP concentration from industrial region also showed higher concentration than other regions. TN concentration in stream water was 5.89 mg/L for industrial region, 3.02 mg/L for urban region and 5.27 mg/L for agricultural region, respectively, suggesting inflow of TN due to fertilizer usage in agricultural field. Relative percentage of nitrogen compounds in TN follows the sequence: $NH_4$ (35.1%) > $NO_2$ (20.0%) > DON (22.8%) > PON (8.9%) > $NO_2$ (3.2%). Concentrations of dissolved nutrients, TP and TN in stream water were 3.2~37.2 times higher than that in Shihwa Lake seawater, therefore large amount of pollutants may be directly entered into Shihwa Lake without any treatment. For Gunja stream of industrial region, pollutants at midstream showed relatively higher concentration compared to upstream and downstream. It is necessary to manage the illegal discharging of sewage and waste water. Our results provide valuable informations on the estimation and reduction of total pollutant loads in the process of establishing adequately strategic and implemental plan of Shihwa Lake TPLMS.

• Korean Journal of Environment and Ecology
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• 제33권6호
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• pp.624-635
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• 2019

Bird strike accidents, a collision between aircraft and birds, have been increasing annually due to an increasing number of aircraft operating each year to meet heavier demand for air traffic. As such, many airports have conducted studies to assess and manage bird strike risks effectively by identifying and ranking bird species that can damage aircraft based on the bird strike records. This study was intended to investigate the bird species that were likely to threaten aircraft and compare and discuss the risk of each species estimated by the single-matrix and multi-matrix risk assessment models based on the Integrated Flight Information Service (IFIS) data collected in Gimpo, Gimhae and Jeju Airports in South Korea from 2005 to 2013. We found that there was a difference in the assessment results between the two models. The single-matrix model estimated 2 species and 6 taxa in Gimpo and Gimhae Airports and 2 species and 5 taxa in Jeju Airport to have the risk score above "high," whereas the multi-matrix model estimated 3 species and 5 taxa in Gimpo Airport, 4 species and 5 taxa in Gimhae Airport, and 2 species and 3 taxa in Jeju Airport to have the risk score above "very high." Although both models estimated the similar high-risk species in Gimpo and Gimhae Airports, there was a significant difference in Jeju Airport. Gimpo and Gimhae Airports are near the estuary of a river, which is an excellent habitat for large and heavy waterbirds. On the other hand, Jeju Airport is near the coast and the city center, and small and light bird species are mostly observed. Since collisions with such species have little effect on aircraft fuselage, the impact of common variables between the two models was small, and the additional variables caused a significant difference between the estimation by the two models.

• Korean Chemical Engineering Research
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• 제50권6호
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• pp.1002-1007
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• 2012

The considerable portion of energy demand has been satisfied by the combustion of fossil fuel and the consequent $CO_2$ emission was considered as a main cause of global warming. As a technology option for $CO_2$ emission mitigation, absorption process has been used in $CO_2$ capture from large scale emission sources. To set up optimal operating parameters in $CO_2$ absorption and solvent regeneration units are important for the better performance of the whole $CO_2$ absorption plant. Optimal operating parameters are usually selected through a lot of actual operation data. However theoretical approach are also useful because the arbitrary change of process parameters often limited for the stability of process operation. In this paper, a theoretical approach based on vapor-liquid equilibrium was proposed to estimate optimal operating conditions of $CO_2$ absorption process. Two $CO_2$ absorption processes using 12 wt% aqueous $NH_3$ solution and 20 wt% aqueous MEA solution were investigated in this theoretical estimation of optimal operating conditions. The results showed that $CO_2$ loading of rich absorbent should be kept below 0.4 in case of 12 wt% aqueous $NH_3$ solution for $CO_2$ absorption but there was no limitation of $CO_2$ loading in case of 20 wt% aqueous MEA solution for $CO_2$ absorption. The optimal regeneration temperature was determined by theoretical approach based on $CO_2$ loadings of rich and lean absorbent, which determined to satisfy the amount of absorbed $CO_2$. The amount of heating medium at optimal regeneration temperature is also determined to meet the difference of $CO_2$ loading between rich and lean absorbent. It could be confirmed that the theoretical approach, which accurately estimate the optimal regeneration conditions of lab scale $CO_2$ absorption using 12 wt% aqueous $NH_3$ solution could estimate those of 20 wt% aqueous MEA solution and could be used for the design and operation of $CO_2$ absorption process using chemical absorbent.

• KDI Journal of Economic Policy
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• 제12권1호
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• pp.93-110
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• 1990

The basic purpose behind the Korean government's policy toward the Korean deep sea fishing industry is to limit growth of the industry. Therefore, the regulations on the industry are generally restrictive and interventionist. The policy is intended to maintain high domestic fish prices in order to protect the domestic coastal fishing industry. Some regulations have also been introduced to maintain "industrial order." Each fishing vessel must obtain a government permit for operation. The permit specifies the kind of fish it can catch, the area of sea in which it can operate, and the port at which it can unload its catches. The number of permits government issues each year is based on the estimates of the demand increase calculated by government officials, and the government traditionally has been fairly conservative in its estimation, reflecting its concern for fish price stabilization, which actually implies a gradual increase of the prices. There is also a restriction on importing vessels from abroad. This regulation is intended to protect the domestic shipbuilding industry. However, this regulation has resulted in an unusually high average age of Korean fishing vessels, causing fishing costs to rise. These regulations and the inflexible response of the regulators to changing circumstances have resulted in many problems: i) high domestic fish prices, which are, to some extent deliberately, inflated to three or four times the level of international prices, resulting in huge consumer welfare losses; ii) over-exploitation of coastal fish resources; iii) provision of a hospitable environment for inefficient firms to survive, which is especially evident from the fact that, despite the high fish prices in Korea, most of the firms in the industry do not enjoy high profitability. It also must be pointed out that the actual beneficiaries of the high fish prices are the large operators, who are protected from competition and provide most of the fish for domestic consumption, rather than the low-income fishing households and small coastal operators whom the policy was originally designed to help. This study proposes a set of regulatory reforms and policy changes which could Promote competition and equity within the industry and allow firms to reduce costs and increase productivity. Such changes can make the industry more efficient and internationally competitive. Major proposals are, among others: minimization of bureaucratic discretion in issuing fishing permits and maintaining transparency in the governments' decision-making processes; reduction of the government permit specifications and simplification of the operational categories within the industry; and removal of the restrictions on importing foreign fishing vessels.

• Korean Journal of Construction Engineering and Management
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• 제16권1호
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• pp.52-63
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• 2015

Business facilities among domestic architectures have rapidly been constructed along with domestic economic development. It is an important facility taking the second largest proportion next to apartment buildings among current 31 building types of fire department classification of 2012 year for urban architectures. The expected service life of business facilities is 15 years, but 70% of those in urban areas have surpassed the 15 year service life as of the present 2014. Thus, the demand for urgent rehabilitation of such facilities is constantly increasing due to the aging and performance deterioration of the facilities'main finishing materials. Especially, the business facilities are being used for the lease of company office or private office, and such problems as aging and performance deterioration of the facilities could cause less competitive edge for leasing and real estate value depreciation for the O&M (Operation & Management) agent and the owner, respectively. Therefore, an effective planned rehabilitation as a preventive measure according to the standardized repair rate by the number of years after the construction is in need in order to prevent the aging and performance deterioration of the facilities(La et al. 2001). Nonetheless, domestic repair/rehabilitation standards based on the repair rate are mainly limited to apartment buildings and pubic institutions, resulting in impractical application of such standards to business facilities. It has been investigated and analyzed that annual repair rate data for each finishing material are required for examination of the applicability of the repair rate standard for the purpose of establishment of a repair plan. Hence, this study aimed at developing a repair rate computation model for finishing materials of the facilities and verifying the appropriateness of the annual repair rate for each finishing material through a case study after collecting and analyzing the repair history data of six business facilities. The results of this study are expected to contribute to the planning and implementation of more efficient repair/rehabilitation budget by preventing the waste of unpredicted repair cost and opportunity cost for the sake of the business facilities' owners and O&M agents.

• Economic and Environmental Geology
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• 제4권4호
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• pp.167-215
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• 1971

I. Purpose and Importance of the Study The purpose of the present study is to clarify to geological, mineralogical, and physico-chemical properties of the clay minerals deposits imbedded in the Tertiary sediments in the areas between. Pohang and Ulsan along southeastern coastal region of Korea. These clays are being mined and utilized for filter and insecticide after activation or simple pulverizing, nontheless activated clays are short coming as chemical industry in Korea has been rapidly grown in recent years. In spite of such increase in clay demand, no goological investigation on clay deposits nor physico-chemical properties of the clays have been carried out up to date. Consequently activated clays produced in Korea is not only of low grade but also of shortage in supply, so that Korea has to import activated clays of better grade. The importance of the present study lies, therefore, on that guiding principle could be laid down by knowing stratigraphical horizons, of clay deposits and fundamental data of improving grade of activated clays might be derived from the results of physico-chemical examinations. II. Contents and Scope of the study The contents of the study are pinpointed down in the following two subjects: 1) General geological investigation of Tertiary formations distributed in the areas between Pohang and UIsan, and detail geological study of the bentonitic clay deposits imbedded in them. 2) To clarifty physico-chemical characteristics of the clays by means of chemical analysis, X-ray diffraction and electron microscope. The scope of the study involves the following there points: i) Regional geological investigation-This investigation has been carried out in order to find out the distribution of Tertiary sediments and exact location of clay mineral deposits in the areas between Pohang and UIsan. ii) Detail geological investigation-This has been concentrated in and around the clay deposits which. had been found out by the regional investigation. iii) Laboratory researchs include i) age determination and correlation of Tertiary sediments by paleontological study, and ii) Chemical analysis, X-ray diffraction, and electron microscopic studies on clays, samples taken from various clay deposits. III. Research Results and Suggestions 1) The geology of the area investigated is composed mainly of Janggi and Beomgokri groups of Miocene age in ascending order rested on the upper Silla system, Balkuksa granite and volcanic rocks of upper Cretaceous age as base. 2) Janggi group is composed in ascending order of Janggi conglomerate, Nultaeri rhyolitic tuff, Keumkwangdong shale, two beds of lignite-bearing formations which consist of alternation of conglomerate, sandstone and mudstone, and andesitic, rhyolitic, and basaltic tuff beds. 3) Beomgokri group is mainly composed of andesitic to rhyolitic tuff interlayered by conglomerate and tuffaceous sandstone. In the areas around boundary between North-and South Kyeongsang-do is distributed Haseori farmation which is composed of conglomerate, sandstone, mudstone and andesitic to rhyolitic tuff, and which is correlated to Eoilri formation of Janggi group. 4) Clay deposits of the area are interbedded in Eoilri, Haseori, Nultaeri tuff, Keumkwangdong shale, upper and lower horizon of the lower lignite-bearing seam, and Keumori rhyolitic tuff formations of Janggi group; and are genetically classi.fied into four categories, that is, i) those derived from volcanic ash beds(Haseori and Daeanri deposits), ii) those of secondary residual type from rhyolitic tuff beds(Seokupri deposits), iii) Clay beds above and beneath the lignite seams, (Janggi and Keumkwangdong deposits), and iv) those derived from rhyolitic tuff beds(Sangjeong and Tonghae deposits). 5) Mineral constituents of clay deposits are, according to X-ray diffraction, montmorillonite accompanied in different degree by cristobalite, plagioclase, quartz, stilbite, and halloysite in rare occasion. The clays are grouped according to mineral composition into four types; i) those consist mostly of montmorillonite, ii) those composed of montmorillonite and cristobalite, iii) those composed of montmorillonite and plagioclase, and iv) those composed of montmorillonite, plagioclase and quartz. 6) Clays interbedded in Haseori formation and vicinity of lignite seams belong to the first type, are of good quality and derived either from volcanic ash bed, or primary clay beds near lignite seams. Clays belonged to other types are derived from weathering of rhyolitic tuff formations and their quality varies depending upon original composition and degree of weathering. Few clays in secondary residual type contain small amount of halloysite. 7) Judging from analytical data, content of silica($SiO_2$) varies proportionally with content of cristobalite, and alumina($Al_2O_3$) content does not vary with that of plagioclase, but increases in the sedimentary bedded type of deposits. 8) It is unknown whether or not these days could be upgraded by beneficiation since no grain size of these impurities nor beneficiation test had been studied. 9) Clay beds derived from valcanic ash layers or sedimentary layers at the vicinity of lignite seams are thin in thickness and of small, discontinueous lenticular shape, although they are of good quality; and those derived from rhyolitic tuff formations or residual type from tuff are irregular in both occurrence and quality. It is, therefore, not only very difficult but also meaningless to calculate its reserve, and reserve estimation, even if done, will greatly be deviated from practically minable one. Consequently, way of discovery and exploitation of clay deposits in the area under consideration is to check the geologically favorable areas whenever needed.

• Journal of Korean Society of Forest Science
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• 제80권3호
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• pp.257-264
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• 1991

Korea has accomplished the afforestation of its forest land in the early 1980's. To meet the increasing demand for forest products and forest recreation, a development of scientific forest management system is needed as a whole. For this purpose the development of efficient forestfire management system is essential. In this context, the purpose of this study is to develop a theoretical foundation of forestfire danger rating system. In this study, it is hypothesized that the degree of forestfire risk is affected by Weather Factor and Man-Caused Risk Factor. (1) To accommodate the Weather Factor, a statistical model was estimated in which weather variables such as humidity, temperature, precipitation, wind velocity, duration of sunshine were included as independent variables and the probability of forestfire occurrence as dependent variable. (2) To account man-caused risk, historical data of forestfire occurrence was investigated. The contribution of man's activities make to risk was evaluated from three inputs. The first, potential risk class is a semipermanent number which ranks the man-caused fire potential of the individual protection unit relative to that of the other protection units. The second, the risk sources ratio, is that portion of the potential man-caused fire problem which can be charged to a specific cause. The third, daily activity level is that the fire control officer's estimate of how active each of these sources is, For each risk sources, evaluate its daily activity level ; the resulting number is the partial risk factor. Sum up the partial risk factors, one for each source, to get the unnormalized Man-Caused Risk. To make up the Man-Caused Risk, the partial risk factor and the unit's potential risk class were considered together. (3) At last, Fire occurrence index was formed fire danger rating estimation by the Weather Factors and the Man-Caused Risk Index were integrated to form the final Fire Occurrence Index.

• Korean Journal of Agricultural and Forest Meteorology
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• 제11권2호
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• pp.72-78
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• 2009

The demand for rainfall data in gridded digital formats has increased in recent years due to the close linkage between hydrological models and decision support systems using the geographic information system. One of the most widely used tools for digital rainfall mapping is the PRISM (parameter-elevation regressions on independent slopes model) which uses point data (rain gauge stations), a digital elevation model (DEM), and other spatial datasets to generate repeatable estimates of monthly and annual precipitation. In the PRISM, rain gauge stations are assigned with weights that account for other climatically important factors besides elevation, and aspects and the topographic exposure are simulated by dividing the terrain into topographic facets. The size of facet or grid cell resolution is determined by the density of rain gauge stations and a $5{\times}5km$ grid cell is considered as the lowest limit under the situation in Korea. The PRISM algorithms using a 270m DEM for South Korea were implemented in a script language environment (Python) and relevant weights for each 270m grid cell were derived from the monthly data from 432 official rain gauge stations. Weighted monthly precipitation data from at least 5 nearby stations for each grid cell were regressed to the elevation and the selected linear regression equations with the 270m DEM were used to generate a digital precipitation map of South Korea at 270m resolution. Among 1.25 million grid cells, precipitation estimates at 166 cells, where the measurements were made by the Korea Water Corporation rain gauge network, were extracted and the monthly estimation errors were evaluated. An average of 10% reduction in the root mean square error (RMSE) was found for any months with more than 100mm monthly precipitation compared to the RMSE associated with the original 5km PRISM estimates. This modified PRISM may be used for rainfall mapping in rainy season (May to September) at much higher spatial resolution than the original PRISM without losing the data accuracy.

• Journal of the Korean Society for Marine Environment & Energy
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• 제10권1호
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• pp.29-43
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• 2007

For effective management of water quality on the southern coast of korea, a three-dimensional eco-hydrodynamic model is used to predict water quality in summer and to estimate the reduction rate in pollutant loads that would be required to restore water quality. Under the current environmental conditions, in particular, pollutant loadings to the study area were very high, chemical oxygen demand (COD) exceeded seawater quality criteria to comply with current legislation, and water quality was in a eutrophic condition. Therefore, we estimated reduction rates of current pollutant loads by modeling. The model reproduced reasonably the flow field and water quality of the study area. If the terrestrial COD, inorganic nitrogen and phosphorus loads were reduced by 90%, the water quality criteria of Region A were still not satisfied. However, when the nutrient loads from polluted sediment and land were each reduced by 70% simultaneously, COD and $Chl-{\alpha}$ were restored. When we reduced the input COD and nutrient loads from the Nakdong River by 80%, $Chl-{\alpha}$ and COD of Region B decreased below $10\;{\mu}g\;1^{-1}$ and $2\;mg\;1^{-1}$, respectively. The water quality criteria of Region C were satisfied when we reduced the terrestrial COD and nutrient loads by 70%. Total allowable loadings of COD and inorganic nutrients in each region were determined by multiplying the reduction rates by current pollutant loads. Estimated high reduction rates, although difficult to achieve at the present time under the prevailing environmental conditions, suggest that water pollution is very severe in this study area, and pollutant loads must be reduced within total allowable loads by continuous and long-term management. To achieve the reduction in pollutant loads, sustainable countermeasures are necessary, including the expansion of sewage and wastewater facilities, polluted sediment control and limited land use.