• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.66-75
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• 2003

This paper reviewed available information/data compiled by various agencies, institutions, and experts, including the academe. The review concentrated on five of the most pressing problems such as air pollution, water pollution, land pollution related to the problem of solid wastes, toxic and hazardous chemical wastes and deforestation. Most of the data presented focused on Metro Manila. Past air monitoring data showed significant exceedances of national air quality guideline values especially for particulates and lead. Many of the country's rivers and lakes have deteriorated, some were declared biologically dead. The acute solid waste problem and the proliferation of toxic and hazardous chemicals have led to the enactment of legislation. Uncontrolled deforestation has taken its toll on the environment and people. Various actions were undertaken by the national administration with the cooperation of other sectors to address environmental problems. However, constraints to the enforcement of environmental laws and programs must be minimized to attain the desired level of environmental protection and management.

• Structural Engineering and Mechanics
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• v.89 no.4
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• pp.399-409
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• 2024

Assessment of existing concrete bridges is a challenge for owners. It has greater economic impact when compared to designing new bridges. When using conventional linear analyses, judgment of the engineer is required to understand the behavior of redundant structures after the first element in the structural system reaches its ultimate capacity. The alternative is to use a predictive tool such as advanced nonlinear finite element analyses (ANFEA) to assess the overall structural behavior. This paper proposes a new reliability framework for the assessment of existing bridge structures using ANFEA. A general framework defined in previous works, accounting for material uncertainties and concrete model performance, is adapted to the context of the assessment of existing bridges. A "shifted" reliability problem is defined under the assumption of quasi-deterministic dead load effects. The overall exercise is viewed as a progressive pushover analysis up to structural failure, where the actual safety index is compared at each event to a target reliability index.

• Sim-seong Yeon-gu
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• v.26 no.1
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• pp.67-88
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• 2011

Pungsu is an ancient logic that systemizes geography based on the Yin-Yang and The Five Elements Principle. It is defined as the unique and highly systemized ancient Eastern art of selecting auspicious sites and arranging harmonious structures such as graves, houses, and cities on them by evaluating the surrounding landscape and cosmological directions. Pungsu helps allegedly one improve life by receiving vital energy(Shengqi, 生氣)-energy flow that flows under the ground. It is traditional belief that the living lead their lives on the ground, indirectly receiving the energy coming out of the ground, whereas the dead are buried under the ground, allowing them to directly absorb energy from the ground, which makes Shengqi the dead receive bigger and more obvious than that the living receive. This energy absorbed by the dead from the ground was believed to be passed on to their descendants. This phenomenon is called "Induction of vital energy between Ancestors and Descendants". People searched for the sites which were believed to contain rich and positive vital energy flow. They also tried to bury their ancestors under such sites hoping to receive the Shengqi coming from underground which they believed would help them thrive and prosper. The efforts to locate the sites which have the most vital energy, auspicious sites or "Bright Yard(明堂)", are easily observed in Asia including China and Korea. The ultimate goal of searching for auspicious sites lies in human(whether alive or dead) receiving vital energy from the nature to enjoy happy lives. In choosing a place to live or to bury their dead ancestors, people tried to understand the energy flow of the site considering the factors related with mountain, water, and direction. If we take a closer look into the methods of finding auspicious sites, we can see that people have tried to see the outer conditions of lands, mountains and waters within the perfect harmony if possible. Auspicious site or Bright Yard is the site with those elements in perfect order and harmony, that is, it is the place which derives the most vital energy from the best order and harmony of nature. As this shows, an auspicious site symbolizes totality-the Self, and it seems to be projected to the land. It is believed to be an attempt that the reason why we try to find auspicious sites to internalize the totality that we projected to the outer world. Therefore, this auspicious site is what our foremost values, symbol of the Self, such as harmony, equilibrium, perfection, and uniqueness are reflected to the land. Through the process of finding such a site, we try to gain totality of psyche.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.427-436
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• 2004

Sedimentation is one of the most common and important units in conventional water treatment plants. Structure such as various baffle walls and inclined plate settler may be obstacles to the horizontal flow when it is poorly designed. Therefore, the effects of these structures on characteristics of hydraulic flow must be evaluated to improve the settling efficiency of the floc. The hydraulic characteristic of the four sedimentations at the three real WTPs (water treatment plants), which have different structural properties respectively inside the settling basin, were investigated by tracer (fluoride) test. The inclined plate settler installed inside settling basin caused a undesirable impact on horizontal flow and produced dead zone. Intermediate baffle and solid baffle wall under the inclined plate settler at GE plant help to minimize the formation of density currents and flow short circuiting. However, installing perforated baffle under the inclined plate settler at other plants could not induce even distribution of flow. NaF used as a tracer was recovered more than 90% at investigated all basin. Morill index ($t_{90}/t_{10}$), Modal index ($t_p/T-HRT$) and short-circuiting index ($[M-HRT-t_p/M-HRT$) were determined from tracer test results performed at three WTPs. Those indices ranged 2.99~3.45, 0.44~0.72 and 0.23~0.47, respectively.

• Ocean and Polar Research
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• v.31 no.4
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• pp.349-357
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• 2009

Ballast water is widely recognized as a serious environmental problem due to the risk of introducing non-indigenous aquatic species. In this study we aimed to investigate measures which can minimize the transfer of aquatic organisms from ballast water. Securing more reliable technologies to determine the viability of aquatic organisms is an important initiative in ballast water management systems. To evaluate the viability of marine phytoplankton, we designed the staining methods of fluorescein diacetate (FDA) and Calcein-AM assay on each target species belonging to different groups, such as bacillariphyceae, dinophyceae, raphidophyceae, chrysophyceae, haptophyceae and chlorophyceae. The FDA method, which is based on measurements of cell esterase activity using a fluorimetric stain, was the best dye for determining live cells of almost all phytoplankton species, except several diatoms tested in this study. On the other hand, although fluorescence of Calcein-AM was very clear for a comparatively longer time, green fluorescence per cell volume was lacking in most of the tested species. According to the Flow CAM method, which is a continuous imaging technique designed to characterize particles, green fluorescence values of stained cells by FDA were significantly higher than those of Calcein-AM treatments and control, implying that the Flow CAM using FDA assay could be adapted as an important tool for distinguishing living cells from dead cells. Our results suggest that the FDA and Calcein-AM methods can be adapted for use on phytoplankton, though species-specific characters are greatly different from one organism to another.

• Water Engineering Research
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• v.3 no.1
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• pp.57-62
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• 2002

This research is intended to integrate long-term operation rules and real time operation policy for conservation & flood control in a reservoir. The familiar Yield model has been modified and used to provide long-term rule curves. The model employs linear programming technique under given physical conditions, i.e., total capacity, dead storage, spillways, outlet capacity and their respective elevations to find required and desired minimum storage fur different demands. To investigate the system behavior resulting from the above-mentioned operating policy, i.e., the rule curves, the simulation model was used. Results of the simulation model show that the results of the optimization model are indeed valid. After confirmation of the above mentioned rule curves by the simulation models, gate operation procedure was merged with the long term operation rules to determine the optimum reservoir operating policy. In the gate operation procedure, operating policy in downstream flood plain, i.e., determination of damaging and non-damaging discharges in flood plain, peak floods, which could be routed by reservoir, are determined. Also outflow hydrograph and variations of water surface levels for two known hydrographs are determined. To examine efficiency of the above-mentioned models and their ability in determining the optimum operation policy, Esteghlal reservoir in Iran was analyzed as a case study. A numerical model fur the solution of two-dimensional dam break problems using fractional step method is developed on unstructured grid. The model is based on second-order Weighted Averaged Flux(WAF) scheme with HLLC approximate Riemann solver. To control the nonphysical oscillations associated with second-order accuracy, TVD scheme with SUPERBEE limiter is used. The developed model is verified by comparing the computational solutions with analytic solutions in idealized test cases. Very good agreements have been achieved in the verifications.

• Journal of Korea Water Resources Association
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• v.31 no.1
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• pp.95-103
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• 1998

Dam sediment can be predicted from the two methods: the one is a physical analysis based on the hydrjulic mechanism and the other is an empirical approach using observed data as a design factor. The former can be used to estimate short-term phenomena by mathematical methods. the latter can be used for deriving long-term design parameters such as dead storage calculation. Monthly reservoir operation is possible with the sluicing efficiency curve based on empirical data. The optimal sediment management can be carried out using the information variable which traces deposit sediments corresponding to the reservoir storage. The idea can provide an optimal operation strategy to save effective storage varying with time. This study presents a methodology for the long-term sediment prediction using sluicing efficiency curve. An application is conducted for estimating accumulated sedment deposit and water supply capability ofr the Fenhe dam in the Yellow rever of China.

• 보존과학연구
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• s.24
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• pp.81-98
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• 2003

The biodeterioration on Iksan Mireuksaji pagoda has been studied with fucus on application of K201 as a chemical treatment. Total of 39species, including 10 algae, 16 lichens, 6 mosses and 7 unidentified bacteria and fungi, were collected and identified on the surface of the pagoda. Most of them caused serious discoloration on the surface. The effectiveness and stability of K201 was examined by applying it on some part of the pagoda. A mild spraying of solution diluted to half of original reagent was good enough to eliminate all the deteriorating species on the surface. Most of discoloration disappeared after the treatment except the red color caused by iron substance. The effectiveness of the regent was compared with water wash. The stone was first washed with water and the dirt on the surface was scrubbed off from the surface. The initial surface of the stone was clearer in water wash. However, many of the deteriorating species reappear in 4 weeks after water wash. Although spraying of the reagent K201 could noteliminate all the remnant of dead organisms as good as scrubbing the surface, no deteriorating algae or lichen was observed until two month after treatment. Therefore, spraying method with chemicals seems more stable and reliable way to remove the biodeterioration than physical scrubbing of the surface.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.271-277
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• 2011

To improve the quality of water from water supply source and to establish the management plan of dead plants in flood control reservoir around Juam Lake, the effect of water quality by dead plant in column with passing time was investigated. In column test, the amounts of release by Carex dimorpholepis were $7,893-7,917mg\;m^{-2}\;month^{-1}$ COD, $2,711-2,816mg\;m^{-2}\;month^{-1}$ T-N and $342-547mg\;m^{-2}\;month^{-1}$ T-P. The amounts of release by Miscanthus sacchariflorus were $6,487-6,507mg\;m^{-2}$ COD, $1,813-1,868mg\;m^{-2}$ T-N and $226-405mg\;m^{-2}\;month^{-1}$ T-P in column. Therefore, the release of COD, T-N and T-P by Carex dimorpholepis were more than those by Miscanthus sacchariflorus Benth in column.

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.315-326
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• 2013

Despite of the importance on the maintenance of a reservoir storage, relatively few studies have addressed the stochastic reliability analysis including uncertainty on the decrease of the reservoir storage by the sedimentation. Therefore, the stochastic gamma process under the reliability framework is developed and applied to estimate the reduction of the Soyang Dam reservoir storage in this paper. Especially, in the estimation of parameters of the stochastic gamma process, the Bayesian MCMC scheme using informative prior distribution is used to incorporate a wide variety of information related with the sedimentation. The results show that the selected informative prior distribution is reasonable because the uncertainty of the posterior distribution is reduced considerably compared to that of the prior distribution. Also, the range of the expected life time of the dead storage in Soyang Dam reservoir including uncertainty is estimated from 119.3 years to 183.5 years at 5% significance level. Finally, it is suggested that the improvement of the assessment strategy in this study can provide the valuable information to the decision makers who are in charge of the maintenance of a reservoir.