• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.42 no.4
• /
• pp.354-359
• /
• 2009

The productivity of ultra-small rotifer, Synchaeta kitina was investigated at the exchange rate of culture water (10, 20, 30, 40 and 50%) and initial inoculation densities (250, 600 and 900 inds. per mL) in semi-continuous culture. Also, the possibility of mass culture was investigated in a 100 L culture tank. Tetraselmis suecica was used as the feed for S. kitina in all experiments. The production of S. kitina increased with an increase in exchange rate of culture water. The highest production ($82.0{\times}10^5$ inds.) was achieved at 40% exchange rate of culture water. The production of S. kitina increased with an increase of initial inoculation density during the first week and the highest total production ($17.4{\times}10^6$ inds.) was achieved at 900 inds. per mL of initial inoculation density. However, on the second week, all treatments were not significantly different in total production (P>0.05). During the two weeks, total production of S. kitina at 900 inds. per mL of initial inoculation density was higher than at 600 inds. of initial inoculation density, but there was no significant difference (P>0.05). In the 100 L culture tank, density of S. kitina was kept from 516 to 890 inds. per mL and S. kitina was daily harvested $15.5{\times}10^6$ to $26.7{\times}10^6$ during the experimental period. The production cost for 100 million rotifers in semi-continuous culture was 63,656 won. The results from this study indicate that the optimal exchange rate of culture water and initial inoculation density for the semi-continuous culture of ultra-small rotifer, S. kitina are 40% and 600 inds. per mL, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.4
• /
• pp.331-339
• /
• 2010

Shrimp farming is the most important mariculture industry on the west coast of South Korea. However, it has suffered from mass mortality due to viral disease outbreaks and coastal pollution due to water discharge. This study developed an intensive shrimp culture method for outdoor ponds, without water exchange, which minimizes the chance of viral transmission from the environment, reduces coastal pollution by water discharge and enhances shrimp production. A culture trial was conducted in two high-density polyethylene (HDPE)-lined ponds with a $550\;m^2$ surface area. The ponds were stocked with postlarvae of Litopenaeus vannamei, the major farmed shrimp species in Korea, on July 10, 2007, and cultured for 90 days with no water exchange. The stocking density of the postlarvae (B.W. 0.0015 g) was $272\;ind./m^2$, which is eight times higher than in traditional pond culture in Korea. At harvest, the total production of ponds 1 and 2 was 1,362kg ($2.48\;kg/m^2$) and 1,282 kg ($2.33\;kg/m^2$), respectively. This is 20~22 times higher than the mean farmed shrimp production ($0.112\;kg/m^2$) in Korea and about eight times higher than in traditional ponds with a good harvest. Although there was no water exchange throughout the culture period, the mean concentrations of unionized ammonia and nitrite-nitrogen were as low as 0.038 and 6.0 mg/L, respectively. The feed conversion rate (FCR) was 1.38, which is 20~45% lower than that of traditional pond cultures. The high efficiency of the diet in this study is thought to be due to a well-managed feeding strategy and well-developed bioflocs used as diet additions for the shrimp. The final body weight of the shrimp at harvest was low (12.2~12.5 g), compared with that of traditional pond culture. This may have resulted from the combination of a short culture period, high density of shrimp, and low temperature. This study suggests that a super-intensive shrimp pond culture method using biofloc technology with no water exchange can minimize viral transmission via water exchange, reduce coastal pollution, and enhance shrimp production.

• The Research Journal of the Costume Culture
• /
• v.28 no.5
• /
• pp.607-620
• /
• 2020

The aim of this study is to define the new expressive techniques for multicolored clamp resist (hyuphill) dyeing, based on empirical verification on relics that are estimated to be dyed by the exchange of more than two wood blocks: a previously undiscovered technique. Clamp resist dyeing (assumed to be made by exchanging wood blocks) have uneven resist printing lines or cloudy gradation. These are reproduced as follows: first, they have uneven contour lines, particularly with the color blue. It is possible to exchange wood blocks separately on patterns with uneven resist printing lines, and it has been verified that the exchange of wood blocks makes these irregular resist printing lines. It has also been verified that exchanging the wood blocks according to the gradation (to emphasize the cubic effect on the patterns) yields clamp resist dyeing with no resist printing lines but with cloudy gradations that have accented borders. This study provides basic information that enables methods of multicolored clamp resist dyeing through wood block exchange to be deduced (something that has not been attempted for a long time). Thus, the revival of the modern Korean dyeing culture based on the conservation and perseverance of the traditional dyeing techniques can be achieved.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.7
• /
• pp.1342-1351
• /
• 2008

The feasibility of the use of Flp-mediated cassette exchange in the development of a CHO cell line, which produces erythropoietin (EPO) stably and largely, was investigated. A stable, high enhanced green fluorescence protein (EGFP)-producing clone was screened by extensive flow cytometric analysis. An EPO expression unit was targeted into the premarked locus of the stable parental clone by Flp-mediated cassette exchange and a correctly targeted clone (FC28T7) was obtained. The EPO production of FC28T7 was proven to be stable in long-term culture. Furthermore, the Flp-mediated cassette exchange did not alter the stable parental clone's characteristics concerning transgene expression level and stability. Taken together, the data obtained here indicated that the establishment of CHO cell lines stably producing a desired protein is achievable using Flp-mediated cassette exchange.

• International Journal of Costume and Fashion
• /
• v.6 no.1
• /
• pp.20-29
• /
• 2006

Once people thought the phenomenon of 'Ha-Han' was only a vogue of young people pursuing oddity. However, when Korean TV series, Korean food, Korean movies and their music penetrated into our life and appeared on TV screens and fashionable magazines, all aspects influence of Korean wave finally arouse people's attention. 'Ha-Han-Zu' is a group of young people who pursue Korean popular culture even imitating their dressing, thoughts and behaviors. This article takes China the original place of Korean wave's popularity as focus, observes the reflection of Chinese to Korean popular culture and discusses the culture exchange phases of Korean wave as the center of popular culture. It can be more detailed that it bases on HOT wave from 1998 to 2004 and analyzes of popular TV series, observes reflects of 'Ha-Han-Zu' to Korean culture, discusses the acceptance to Korean popular culture and what kind of active reflection consumption giving to culture exchange.

• International Journal of Advanced Culture Technology
• /
• v.7 no.1
• /
• pp.84-88
• /
• 2019

This paper examines whether the exchange rate respond differently to monetary policy shocks in Korea using regression model. We find an asymmetric response of the monetary policy shocks to the monetary policy shocks in the context of Korea. Over the whole period sample, we do not find the effect of an actual interest rate on exchange rate. But we find that the estimated coefficient on the expected and unexpected change in the policy rate are negative and statistically significant. In the period of monetary policy easing, the estimated coefficient on the expected and unexpected change in the policy rate are negative but not statistically significant. In contrast, the period of monetary policy tightening, the estimated coefficient on the expected and unexpected change in the policy rate are negative and statistically significant.

• Journal of Aquaculture
• /
• v.18 no.2
• /
• pp.115-121
• /
• 2005

This study was performed to investigate the formation and mass production of resting eggs by freshwater rotifer, Brachionus calyciflorus as influenced by different aeration supplements and exchange intervals of culture water in 15-L culture vessels and 500 L culture tanks. The maximum densities and mixis rates of the rotifers were not different between experimental group exposed to air or oxygen supplements. However, the fertilization rate and formation of resting eggs of the rotifers in the air-supplemented group were significantly higher than those in the oxygen supplemented group. In the experiment concerning exchange interval of culture water, the maximum density of the rotifers and formation of resting eggs in the batch culture were significantly higher than those in the semi-continuous culture with exchange of water every day. The formation of resting eggs per Chlorella dry weight was highest in the semi-continuous culture with exchange of water every day. The resting eggs of rotifers were produced at a density of $51.8{\sim}57.9{\times}10^6$ eggs in 500-L culture tanks. In this study, the batch culture with air is an effective method for mass production of resting eggs by the freshwater rotifer, B. calyciflorus, and the efficiency of mass production of resting eggs by this rotifer was similar to that of the seawater rotifers, B. plicatilis and B. rotundiformis.

• The International Journal of Costume Culture
• /
• v.5 no.2
• /
• pp.37-41
• /
• 2002

• Proceedings of the Costume Culture Conference
• /
• 2001.10a
• /
• pp.3-7
• /
• 2001

• International Journal of Advanced Culture Technology
• /
• v.11 no.3
• /
• pp.236-246
• /
• 2023

This study aims to understand microaggressions directed toward international students from the perspective of international exchange professionals, who tend to be in relatively close contact with international students. This study targeted professionals who directly advise and support international students at university international exchange centers in J and G cities. The data were collected by conducting focus group interviews with seven participants in two groups from 25 May to 8 June 2023. Data were collected by conducting focus group interviews of seven participants in two groups from 25 May to 8 June 2023. After analyzing the interview data using thematic analysis, two themes emerged: the experiences of international students and the perspectives of international exchange professionals. The experience of international were further categorized into three sub-themes: differences in cultural context, academic discrimination, and discrimination due to lack of information. The perspectives of international exchange professionals were further categorized into three sub-themes: limited access to infrastructure, different perspectives depending on the level of the country, and consideration as a barrier. It is hoped that the findings of this study, obtained by exploring the microdiscrimination faced by international students at universities, will facilitate the development of different systems and policy recommendations to improve the experiences of international students.