• Journal of Korea Water Resources Association
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• v.45 no.3
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• pp.331-347
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• 2012

The downstream of the Nam River Dam is crucial region for long-term water resource planning for Busan and Gyeongnam Province. Thus, the analysis of flow behavior and water quality is necessary for the sustainable surface water management and the control of pollutant source. In this study, the flow field and BOD transport at the downstream of Nam River Dam were analyzed by incorporating 2-D water quality model, RAM4 and 3-D water quality model, WASP with the hydrodynamic model, RAM2 and EFDC, respectively. The application of 2-D flow analysis model, RAM2 showed that velocity distributions at the five transverse sections of the meandering part closely followed the measured values by ADCP, and the flow field and overflow characteristic at the submerged weir showed satisfactory performance compared with the result of 3-D EFDC model. In addition, the BOD concentration field obtained by RAM2-RAM4 coupled modeling was in good agreement with the result by EFDC-WASP model throughout the computational domain. The hydrodynamic characteristic and water quality at the downstream reach of Nam River Dam are mainly influenced by the Dam discharge, and the water quantity is closely related to the water quality control and fishery environment at the lower part of Nakdong River. Therefore, when further quantitative analysis is necessary regarding these issues, 2-D semi-coupled modeling is recommended in terms of computational effectiveness and model application aspect.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.957-964
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• 2017

This study was carried out to investigate the effects of garlic extract on histamine reduction in mackerel meat stored at $4^{\circ}C$ and $15^{\circ}C$, respectively. The number of total bacteria in mackerel meat treated with 7.5% garlic extract was ten times lower than that of the control stored for 6 days of $4^{\circ}C$. However, there was no difference among the samples after 9 days of storage. Reduction of eicosapentaenoic acid (C20:5) and docosahexaenoic acid (C22:6) contents was observed in the normal control group at both temperatures. However, contents of these two polyunsaturated fatty acids slightly increased in garlic extract-treated fish. Amounts of volatile basic nitrogen increased over time in the control group, but decreased in the garlic extract-treated meat, indicating that garlic extract might suppress decomposition. No histamine was detected initially in all samples. However, a small amount of histamine (42.87 mg/kg) was detected in the control at 3 days after storage at $4^{\circ}C$. Histamine content increased continuously with storage period but was lower in mackerel meat containing garlic extract, in which histamine suppression was proportional to the concentration of garlic extract. It can be concluded that garlic extract could be utilized to extend the storage period of mackerel.

• Journal of Mushroom
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• v.14 no.3
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• pp.100-104
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• 2016

Mushroom flies are one of the most serious threats to mushroom production and cultivation in Korea, and they cause significant losses in yield and quality. In this study, we investigated the occurrence and control of mushroom flies in farms where Agaricus bisporus was cultivated in Chungnam. The cultivation period was more than 7 years in the 32 mushroom farms examined; about 28% were environment-friendly cultivation farms, and 72% were conventional cultivation farms. Mushroom flies were a major pest in about 84% of the examined farms. Most of the mushroom flies were sciarids and phorids (71% and 24%, respectively). The adult flies were found throughout the year, but their occurrence was the highest in September when the temperature increased. In general, the occurrence of mushroom flies in the examined farms was high; however, insect nets and post-crop steaming programs used as basic control methods were not implemented properly. Our findings show that integrated pest management of mushroom flies is urgently required for A. bisporus cultivation in Korea.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.7-30
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• 1998

Generation and recycling potential of organic waste in Korea were estimated. Status of organic waste composting and compost utilization also were surveyed to promote the recycling of organic waste. From 1994 to 1997, generation of garbage decreased gradually while recycling rate increased due to positive governmental strategy. During the same period, livestock waste increased 11.2%. Municipal wastewater sludge was generated 3,500 ton/day which was 0.03% of wastewater treated in 1996. The energy Potential of industrial organic waste was estimated to 288 million TOE which was 1.75% of the nationwide first energy consumption in 1996. Recycling of industrial sludge was low to 31%, while recycling of animal waste, plant scraps, and wasted paper were relatively high over 50%. Industrial sludge should be recycled more as it was the most part of industrial organic waste. Conventional composting materials were mainly livestock waste, food processing waste, fishery waste, sawdust, and nightsoil. Garbage and sludge have been composted recently. 420,000 tons of compost in 1996 were produced by 288 makers, the most of which were utilized in agriculture. It was suggested that separated collection, compost standard, and quality management should be provided to promote the composting of organic waste.

• Fisheries and Aquatic Sciences
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• v.23 no.6
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• pp.16.1-16.10
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• 2020

This study was conducted in Lake Hayq between January and December 2018. The objectives of this study were to determine the growth, condition, sex ratio, fecundity, length at first sexual maturity (L₅₀), and spawning seasons of common carp (Cyprinus carpio). Monthly fish samples of C. carpio were collected using gillnets of stretched mesh sizes of 4, 6, 7, 8, 10, and 13 cm and beach seines of mesh size of 6 cm. Immediately after the fish were captured, total length (TL) and total weight (TW) for each individual were measured in centimeters and grams, respectively, and their relationship was determined using power function. Length at first maturity (L₅₀) was determined for both males and females using the logistic regression model. The spawning season was determined from the frequency of mature gonads and variation of gonadosomatic index (GSI) values of both males and females. Fecundity was analyzed from 67 mature female specimens. The length and weight relationship of C. carpio was TW = 0.015TL^2.93 for females and TW = 0.018TL^2.87 for males that indicate negative allometric growth in both cases. The mean Fulton condition factor (C_F) was 1.23 ± 0.013 for females and 1.21 ± 0.011 for males. The value of C_F in both cases was > 1 that shows both sexes are in good condition. Among the total 1055 C. carpio collected from Lake Hayq, 459 (43.5%) were females and 596 (56.5%) were males. The chi-square test showed that there was a significant deviation between male and female numbers from 1:1 ratio (χ²= 22, df = 11, P > 0.05) within sampling months. The length at first sexual maturity (L₅₀) for females and males were 21.5 and 17.5 cm, respectively. Males mature at smaller sizes than females. The spawning season of C. carpio was extended from February to April, and the peak spawning season for both sexes was in April. The average absolute fecundity was 28,100 ± 17,462. C. carpio is currently the commercially important fish while Nile tilapia fishery has declined in Lake Hayq. Therefore, this baseline data on growth, condition, and reproductive biology of common carp will be essential to understand the status of the population of carp and design appropriate management systems for the fish stock of Lake Hayq, Ethiopia, and adjacent countries.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.185-191
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• 2013

This study were classified the type of fishway installed on the tributary of Nakdong River, and analyze the state was to establish a management plan. As a result showed low installation ratio of fishway which includes 9,164 weirs at the 786 streams of the tributary of Nakdong River and 1,263 fishways. The type of fishway is shown as 62% for standard type and 38% for non-standard type. Assessment results of fishway condition, the ones in good condition, moderate and poor condition fishways are examined as 28%, 66%, 6%, respectively. In the past, there happened to install the fishways without discussing with fishery research institution but it is judged to install the verified fishways through powerful legal remedy and enable each community to control the fishways voluntarily through the support of government after installing the fishways.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.1-8
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• 1991

Population dynamics of Matted sole Limanda yokohamae($G{\"{U}}NTHER$) in Tokyo bay, Japan has been studied by virtual population analysis (VPA) for multi cohort and experimental fishing. Based on the biological data, the present parameters of the Limanda yekohamae stock at the Tokyo bay, Japan were estimated as follows: natural mortality coefficient(M) were 0.313 for male and 0.250 for female, terminal fishing mortality coefficient(F) were 2.190 for male, and 0.798 for female, rate of exploitation(E) was $30\%\;to\;50\%$. From the result of virtual population analysis for multi cohort, the population size were estimated from 3,5000,000 to 9,200,000 fishes, according to the result of experimental fishing, estimated stock size were 2,400,000 to 8,700,000 fishes. Stock size difference of the two methods were about two times in 1987, however, other years has been showed from 0.8 to 1.5 times. Both method has been showed same increase and decrease tendency of the c. p. u. e. and catches. From the isopleth diagram plot by Beverton and Holt's yield per recruit, the catches could be increase two times for female, 1.3 times for male than present aspects by the fishing management. And further, as reducing fishing effort, extension of mesh size and rising the length at first caputre, are reasonable in order to manage the stock at the optimum level.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.247-252
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• 2014

Despite the facts that navigation technology and educational programs were developed, and that maritime law has been enforced strictly, the number of maritime accidents has not dropped significantly. Accident prevention is emphasized because of the extreme life, property, and environmental losses that accompany maritime accidents. Even though there are a variety of preventive activities, their performance is not satisfactory. In order to promote preventive activities and to organize safety management, a Preventive Index of Ship Accident(PISA) and a Preventive Level of Ship Accident(PLSA) which are abstracted from the statistical data of ship accidents (2009~2013) are proposed. The survey module by which these variables can be calculated is composed of preventive domains such as education, engineering, enforcement and information, and is applied for the preventive indexes measurement of cargo, passenger, tanker, tugboat and fishery ships. We compared and analyzed measured result with statistical accident rates and cases to confirm the index utilities. It was found that there is some correlation between the index value and the ship accident rate. It is expected that this index will become useful to evaluate a preventive status for the prevention of ship accidents and for the maritime safety culture.

• Journal of Distribution Science
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• v.13 no.7
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• pp.53-61
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• 2015

Purpose - This research analyzes overseas expansion support systems for small- and medium-sized enterprises in Germany and Japan. Germany and Japan have developed overseas expansion support policies for such enterprises. The study then explores the implications for Korea and its local governments. Research design, data, and methodology - We did a comparative analysis of Japan and Germany and their support for overseas expansion of small and medium companies. Data were mainly collected from the Ministry of Economy, Trade and Industry (Japan) and the Germany Trade and Invest (Germany) agency through statistics and literature surveys, and analysis studies. Results - First, human resources cultivation and funding support policies, which both Germany and Japan use as part of small- and medium-sized enterprise policies, should be modified to Korean circumstances and to reflect its own small- and medium-sized enterprise support needs. Second, both the German policies that support overseas expansion of small- and medium-sized enterprises and those of Japan's include the philosophy and methods that put an emphasis on these enterprises, despite the fact that there are big differences in the overseas policies in these two countries. Third, German and Japanese governments are embracing the idea that small- and medium-sized enterprises are key to their national economies and implementing policies based on the ratio occupied by these enterprises in the domestic consumption or GDP. In other words, Germany and Japan consider small- and medium-sized enterprises as central to their nation's industry, and assess them as economic industry that should definitely exist for the continued survival of big businesses, and not just as merely supplemental to big business. Fourth, whereas Germany emphasizes support to product exhibition in its overseas expansion support policies, Japan is providing integrated support containing foreign direct investment to small- and medium-sized enterprises. Fifth, there are differences in the overseas expansion support in Germany and Japan in terms of their support to big business. Whereas Germany considers support to big business unnecessary, Japan is implementing active support policies to areas corresponding to big business. Korea will have to benchmark the policies of Germany and Japan, and decide whether or not to give full support to small- and medium-sized enterprises, while excluding areas supporting big business. Conclusions - Based on this analysis of German and Japanese overseas expansion support policies, we need to choose the policies that will engender a solid outcome and derive modified policies for the circumstances of Korea. Additionally, we can use the comparison of the overseas support policies of Japan and Germany to choose small- and medium-sized enterprise overseas expansion support policies for Korea. However, we cannot provide specific overseas support policies by industry. This point will be referenced as a limitation of this study. In future research, we expect that some researchers will take an empirical approach to exploring Korean overseas expansion support through collecting cases of overseas support policies and interviewing policy authorities.

• Journal of Fisheries and Marine Sciences Education
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• v.9 no.1
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• pp.71-82
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• 1997

The squid fishery from the East China Sea has increased in importance in recent years, for management of resources were carried out selection experments using diamond and square mesh cod-end with enclosing small mesh cover net by trouser net method during 1991-1994 year. Mesh selection studies on Short-finned squid and Long-finned squid divided from catches by trial experiments. The results that square mesh cod-end retained proportionally fewer small and undersized Short-finned squid and Long-finned squid, square mesh cod-end were greater selection factor and 50% selection length than diamond mesh cod-end.