• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.202-207
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• 1987

Esterifying conditions to produce propylene glycol alginate (PGA) with alginic acid and propylene oxide were determined, and physico-chemical properties of the PGA were also determined. The rate of esterification increased with the content of propylene oxide up to 4 mole. Alginic acid containing $30\%$ of water shelved maximum esterification, however, it was dificult to remove the surplus moisture in the alginic acid when it cotained the moisture above $70\%$. Maximum esterification was taken place when alginic acid with $44.15\%$ water was reacted with 4mole of propylene oxide at $70^{\circ}C$. The rate of esterification of alginic acid with $50.05\%$ of water increased up to 1 hour at $70^{\circ}C$, followed by no significant increase with reaction time. No significant decrease in the viscosity of $2-3\%$ PGA solution occurred, up to pH 3.0. Pseudoplastic characteristics were kept in case of $1\%,\;2\%\;3\%$ and $5\%$ of PGA solution in the pH of 1.0-5.0.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.3
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• pp.219-226
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• 2005

The result that analyze for 6 years a groundwater influx quantity of total 60 catch-pit established in subway line 5 appeared with $0.77m^3/min$. When comparing design approaches of the catch-pit with design approaches of the box structure $2m^3/min$ and the tunnel structure $3m^3/min$, it is found that it has a surplus. Red sedimentation substance contains large portion of Fe. The earth retaining structure of a tunnel and groundwater containing more portion of Fe than other area rue the major factor of this substance. In case of white sedimentation substance, the most frequently founded ingredient is CaO, which is occurred in case grouting injection materials for ground reinforcement is transmitted into a tunnel system by ground water. This substance is doesn't affect safety of a tunnel.

• Survey Research
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• v.3 no.2
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• pp.47-76
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• 2002

Starting point bias arises in the iterative bidding framework when the initial bid influences respondent's final bids. The bidding game has become the most commonly used method of asking the valuation question in contingent valuation studies. A bidding game is typically conducted by either personal or telephone interview. Bidding begins with an interviewer positing an initial bid (starting bid) to a respondent. If the respondent is willing to pay the initial bid, the interviewer revises the bid upward until a negative respondent is obtained. A negative response to the initial bid downward until an acceptable amount is found. The final bid is a measure of the respondent's Hicksian compensating or equivalent surplus for the item being valued. This paper explicity tested for starting point bias in bidding games. That is, it was asked whether final bids are influenced by the magnitude of the starting bids in the process of valuating the WTP when to improve the quality of running water in Seoul and its vicinity. The result shows staring point bias exists in the present data and its magnitude is ${\delta}$=-0.265237.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.62-66
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• 2003

Mass consumption of the surplus onion in the period of harvesting season by processing to various value-added functional food products would be one of the counterplot for stable market. This study was to develop functional sponge cakes with addition of onion powder, using physiochemical properties and sensory evaluation. The specific gravity and viscosity tended to increase according to the addition of onion powder. The water content was highest mark on the 4% onion powder added-cake. The color of lightness, yellowness, and redness of cake crust tended to decrease with the addition of onion powder. The addition of onion powder showed decrease in lightness and yellowness and increase in redness of cake crumb. The specific loaf volume was superior with the addition of 4% onion powder. The resilience, fracturability and adhesiveness showed a difference from the control. Sensory evaluation of cake indicated that addition of onion powder especially at the level of 2, 4%, enhanced appearance flavor, mouth feeling, and overall acceptability.

• The Journal of Fisheries Business Administration
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• v.34 no.1
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• pp.69-85
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• 2003

The primary objective of this thesis is to study, case by case, the international disputes for fishing rights between fishing nations and costal states never imagined till the introduction of the UN Convention on the Law of the Sea adopted in 1982 and came into effect in November 16, 1994, which governs the high seas and EEZ in a new manner. Such a study is to provide help in the understanding on this new marine system and how to deal with. This is addressed by the perspectives of disputes (a) in the high seas between fishing nations having traditionally enjoyed the principle of the freedom of the high seas and costal states, (b) in the EEZ between fishing nations and costal states possessing the exclusive jurisdiction over living marine resources and sovereign rights for determining allowable catch and the surplus in its EEZ. The article can be divided into four main parts. First, both the general principles of the settlement of international disputes, and the nature and procedures described in the UNCLOS are introduced. Second, it gives cases of tuna long-liner, North Pacific trawler and squid jigger occurred in the coastal states EEZ, and analyses the problem in both terms of its background and final judgment. It further describes the possible issues in case it depends on the International Tribunal for the Law of the Sea for its settlement. Third, closely tied to above, important points such as the right of hot pursuit, prompt release of vessel and crew, and the limits of cooperation with costal states inspector on board fishing vessels are considered mostly based on the UNCLOS, Bilateral Agreement and UNIA. Finally, the article concludes as follows ; The need for broad analyses on the nature of international suits and legal system for the settlement, to win the case before the International Tribunal for the Law of the Sea or coastal states court, is really acknowledged. However, considering the lack of previous studies about it, it is preferably recommended that governmental efforts for making legal standards to cover the judicial costs, for helping industry out of becoming bankrupt.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.29-37
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• 2008

In this work, it was investigated that various aspects of process, application situation, merits and short-coming results of the thermophilic methane fermentation with highly concentrated organic waste substances such as sewage sludges, food wastes and excretions. The merits of this methane fermentation were that it had a very fast reaction rate and was possible to proceed in high loads. It was also high in mortality for pathogenic microorganism and the digested sludge was more hygienic. However, the short-comings were that more energy was required for heating in the fermentation facility, no surplus energy could be gained from low concentration of organic waste, the fermentation treatment dropped level of water quality, thus burdens discharging process of water. Especially, the high concentration of methane fermentation could possibly lack nutritious salt and could face the disturbance by ${NH_4}^+-N$, a proper alternative was required. In general, thermophilic methane fermentation was considered as a better mean in disposing of cow excretion and food waste which were highly concentrated organic wastes. On the other hand, under the condition where the concentration of waste material was low and the high concentrate waste material became higher than 3,000 mg/L in ${NH_4}^+-N$, thermophilic methane fermentation resulted less desirable outcome.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.95-104
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• 2005

The research conducted to study the potential practicability of recycled aggregate concrete by analyzing the characteristics of concretes made of recycled quality aggregates produced by wet and dry process has found the following results. The air content of recycled aggregate concrete increased with increase of the substitut on rate due to mortar included while producing recycled aggregates. However, the concretes with aggregate produced by dry process had relatively low rate of increase in air content. The slump showed generally decreasing trend as the substitution rate of recycled aggregate increased regardless of the wet or dry process. It was assumed that the mortar particles remained in recycled aggregate absorbed the surplus hydration in concrete and decreased fluidity The compressive strength generally decreased as the substitution rate of recycled aggregate increased, however there was an increasing trend as well due to decreasing effect of water-cement ratio when the substitution rate of recycled aggregate reached 25, 50% after mix. This phenomena also appeared in early age, which meant that recycled aggregate concrete should not be retarded in setting when applied in the field. The tensile strength also reached the maximum when wet or dry recycled aggregate replaced with 25%. To conclude, recycled aggregates for concrete produced by wet or dry process are expected to demonstrate essential characteristics of concrete without significant decline in physical or dynamic quality when the substitution rate is below 25% although there are variations subject to water-cement ratio. However, slight differences are expected due to types of recycled aggregate and physical quality.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.453-457
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• 2016

In various industrial plants such as power generation plants, petrochemical plants, and unit factories, there is an increasing demand for a system that generates hot water using waste or surplus steam. Compact steam unit (CSU), which produces hot water by using steam, is a good solution considering energy reuse. In this study, as a basic study to develop a high-pressure CSU, heat transfer characteristics of a hybrid heat exchanger were investigated through experiments, in order to use the hybrid heat exchanger instead of a conventional plate heat exchanger as the core component of CSU. The experimental results are the followings. Heat balance between the hot side and cold side was satisfied within ${\pm}5%$. Overall heat transfer coefficient increased linearly as the Reynolds number increased and exceeded $5,524W/m^2K$ when the flow velocity was above 0.5 m/s. In addition, pressure drop also increased as the Reynolds number increased, and pressure drop per unit length was below 50 kPa/m.

• Journal of Korea Water Resources Association
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• v.51 no.4
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• pp.301-311
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• 2018

Recently, the flood inundation caused by heavy rainfall in urban area is increasing due to global warming. The variability of climate change is described in the IPCC 5th report (2014). The precipitation pattern and hydrological system is varied by climate change. Since the heavy rainfall surpassed the design capacity of the pipeline, it caused great damage in metropolitan cities such as Seoul and Busan. Inundation in urban area is primarily caused by insufficient sewer capacity and surplus overflow of river. Inundation in urban area with concentrated population is more dangerous than rural and mountains areas, because it is accompanied by human casualties as well as socio-economic damage to recover destruction of roads, brides and underground spaces. In addition, various factors such as an increase in impervious area, a short time of concentration to outlet, and a shortage of sewer capacity's lack increase flooding damage. In this study, flood inundation analysis was conducted for vulnerable areas using XP-SWMM. Also, three structural flood prevention measures such as drainage pipeline construction, detention reservoir construction, and flood pumping station construction are applied as flood damage prevention alternatives. The flood data for each alternative were extracted by dividing the basin by grid. The Spatial Compromise Programming are applied using flood assessment criteria, such as maximum inundation depth, inundation time, and construction cost. The purpose of this study is to reflect the preference of alternatives according to geographical condition even in the same watershed and to select flood defense alternative considering regional characteristics.

• Journal of the Korean Society for Railway
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• v.17 no.4
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• pp.251-259
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• 2014

The transition zone between an earthwork and a bridge effect to the vehicle's running stability because support stiffness of the roadbed is suddenly changed. The design criteria for the transition structure on ballast track were not particular in the past. However with the introduction of concrete track is introduced, it requires there is a higher performance level required because of maintenance and running stability. In this present paper, a transition structure reinforced with geosynthetics is suggested to improve the performance of existing bridge-earthwork transition structures. The suggested transition structure, in which there is reinforcing of the approach block using high-tension geosynthetics, has a structure similar to that of earth reinforced abutments. The utilized backfill materials are cement treated soil and gravel. These materials are used to reduce water intrusion into the approach block and to increase the recycling of surplus earth materials. An experiment was performed under the same conditions in order to allow a comparison of this new structure with the existing transition structure. Evaluation items are elastic displacement, cumulative settlement, and earth pressure. As for the results of the real-scale accelerated testing, the suggested transition structure has excellent performance for the reduction of earth pressure and settlement. Above all, it has high resistance the variation of the water content.