• Journal of Aquaculture
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• v.21 no.4
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• pp.339-345
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• 2008

Farming of the fleshy shrimp Fenneropenaeus chinensis which is a major cultured species in the west coast of South Korea, has been suffered :trom mass mortality due to disease epizootics including viruses. Since the Pacific white shrimp Litopenaeus vannamei was introduced to Korea in 2003, farming of this species has rapidly increased for years, occupying 62.5% of total cultured shrimp production in 2007. However the studies on L. vannamei culture methods for shrimp farming situations in Korea are very limited. Nursery culture of shrimp larvae has some advantages including increased survival, improved feed efficiencies, enhanced growth performance and reduced grow-out period. In this study, L. vannamei postlarvae (${PL_3}-{PL_{10}}$) with a density of $3,750-9,090/m^3$ were cultured in four raceways under limited water exchange condition for 35 days. Survival was the highest (93.6%) in tank stocked with $4,090/m^3$ and was the lowest in tank with $9,090/m^3$ (58.1 %). Mean body weight at harvest ranged from 0.071 to 0.108 g, and FCR was 0.59-0.70 in all tanks. Concentration of total ammonia nitrogen was increased up to 20 ppm on day 10 in all tanks and thereafter gradually decreased by the third week of culture. Nitrite-nitrogen was rapidly increased from the third week, representing bio-floc condition by developed nitrifying bacterial community. Of the present nursery system some modification of structure and consideration for commercial scale are needed in order to be implemented to shrimp farmers.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.106-110
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• 1991

The mode of inheritance of resistance to fenvalerate in the diamondback moth (Plutella xylostella L.) was studied using insecticide susceptibility and mixed function oxidase tests. Tehre were no differences in the concentration-mortality relationships between $F_1$ progenies $(S_{female}\timesR_{male},\;R_{female}\timesS_{male})$ obtained from reciprocal crosses with the susceptible and fenvalerate-selected strains(R), indicating the absence of sex-linked inheritance. Degree of dominance of the $F_1$ progenies $(S_{female}\timesR_{male},\;R_{female}\timesS_{male})$ were -0.50 and -0.46, respectively, in the insecticide susceptibility test and -0.85 and -0.81, respectively, in the mixed function oxidase test. These results suggest that inheritance of fenvalerate resistance is controlled by and incompletely recessive autosomal gene.

• Journal of Aquaculture
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• v.3 no.1
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• pp.39-48
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• 1990

The growth response of the yellow perch, a highly proteinaceous food feeder in nature, to different protein levels (50, 40 and $27\%$) in formulated diets was determined over a 20-week period. Approximately $23\%$ of dietary protein could be spared by substituting less expensive carbohydrate and lipid materials without any noticeable ill-effects or reduction in weight gains. In turn, there was no statistically significant difference between total weight gains of fish fed at three different levels of protein diets, although fish on the 50 and $40\%$ protein diets grew better in the first few weeks. A shift in the protein requirements occur-red after about 10 weeks of rearing. Growth efficiencies(growth/food intake) became nearly the same at all levels of protein and decreased consistently throughout the remainder of the study period. The results indicate that young yellow perch(6g initial weight) can grow normally with the $27\%$ protein diet after about 10 weeks of initial feeding with higher protein diets(or regular commercial diets).

• Journal of Aquaculture
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• v.20 no.4
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• pp.212-218
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• 2007

Reproductive biology (sexual maturity and reproductive cycle) of starry flounder Platichthys stellatus were examined by histological methods. From March 2004 to February 2005, 144 females and males were sampled. Gonadosomatic index (GSI) of female and male were peaked in May and February, respectively. Monthly changes of hepatosomotic index (HSI) showed a negative correlationwith those of the GSI. Changes of condition factor (CF) in female were correlated with gonad maturation, while that of male were no difference all the year round. Based on monthly GSI and gonadal development the reproductive cycle of starry flounder could be divided into four stages: growing stage (September to November), maturation stage (September to February), ripe and spent stage (March to May), and recovery and resting stage (June to August). Biological minimum size of female was 1,074 g. The relationship between fecundity (F) and body weight (BW) of the fish was expressed as $F\;=\;455.86BW^{1.2006}$.

• Journal of Aquaculture
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• v.16 no.4
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• pp.252-256
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• 2003

Effluent from farm trefish contained high concentrations of nitrogen and phosphorus, such kinds of nutrients were released to the environment without proper treatment and thses increased the pollution of the environment. We evaluated the conventional treatment system with cost effective ecotechnologies for the removal of nutrients. Water lettuce chambers were investigated under the various experimental conditions to improve the efficiency of N&P removal and the treatment of from aquaculture effluent. In this research, six water lettuce chambers (80 liter each) received combination of aquaculture wastewater effluent at hydraulic retention times (HRTs) of 1, 2, 4 and 8days. The water lettuce chambers operated at a 8 day HRT investigated for aquaculture effluent (1'st) showed average removal efficiency, BOD, T-N, T-P of 92.8, 79.0 and 93.6% on average respectively.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.149-157
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• 2019

This study interested on management of broodstock and the effect of raise the temperature for promotion of maturity in Tresus keenae. For management of broodstock, we performed indoor and outdoor culture. In addition, broodstock was put in exposure and immersion condition. This experimental design is aimed at knowing the optimal management of broodstock. In addition, we investigated the promotion of maturity, growth and survival rate when raise the temperature of the breeding seawater of broodstock in winter season. Result that, the management of broodstock was shown to be more effective obesity and survival rate in outdoor culture than indoor culture. In addition, there is no anthropogenic food supply in management and it is easy to management because it is kept under natural environmental conditions. Therefore, It is considered appropriate to management to outdoor culture. In raise the temperature, survival rate was lower in the experimental group than in the control group. However, obesity was significantly increased compared with the control group. Also, gonad showed that the sex maturity was promoted. If sex maturation is not developed due to seasonal water temperature, the promotion of sexual maturity through heating is considered to be an effective method in terms of artificial seed production.

• Journal of Aquaculture
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• v.22 no.1
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• pp.42-50
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• 2009

Shrimp farming which is entirely conducted in outdoor ponds in the west coast of Korea has been suffered from mass mortality due to viral epizootics. Intensive indoor shrimp culture under limited water exchange can solve these problems of outdoor ponds including viral transmission from environment, pollution due to discharge of rearing water, low productivity and limited culture period. In this study, juvenile L. vannamei (B.W. 0.08-0.09 g) was stocked with $3,000-5,455/m^3$ in density in four raceway tanks (two $12.9\;m^2$, two $18\;m^2$ tanks) and cultured for 42 days with 2.7-3.4% of daily water exchange. Results from four tanks showed FCR of 0.79-1.29, survival of 38.2-48.0%, and yields of $2.49-4.22\;kg/m^3$ which is consistent with 12-20 and 8-14 times higher than those of commercial shrimp hatchery and outdoor pond in Korea, respectively. Concentrations of total ammonia nitrogen in all four tanks were 1.11-1.42 ppm in mean level and did not exceed 6.0 ppm (0.096 ppm of $NH_3$) which is still acceptable levels for shrimp growth. During the culture trial, concentration of $NO_2$-N rapidly increased from stocking, resulting in mean concentration of 18.45-22.07 ppm. It also exceeded 10 ppm over four weeks and maintained at 35-45 ppm for four days in all tanks, accounting for low survival of shrimp due to long-term exposure to high concentration of $NO_2$-N. Nevertheless, the results with survival rate over 38% from raceways which experienced the extreme $NO_2$-N levels suggests that under "biofloc system" white shrimp can acclimate to high $NO_2$-N concentration to some degree.

• Korean Institute of Interior Design Journal
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• v.19 no.4
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• pp.11-21
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• 2010

The purpose of this study is to examine the design characteristic of the facade of the main adminstration building in university. The main administration building which is a basic of educational facilities has various administration setups, such as the register's office, the student affairs section, the planing department, the general affair's office and so on. This building performs academic, administration, facilities management, and admissions service. Also, the building has an ideological, historical, and symbolic image, having an organic relationships with the other educational facilities. This study choose one hundred seven universities, except universities that does not provide information easily and the second campus which does not have the main administration building, as the subjects of the study. The analysis is derived from the design elements applied to facade design of the main administration building and this is divided into design principles(balance symmetry, contrast, rhythm), the formal composition(geometrical, linear), and the style of architecture(classical architecture and modern architecture). The results of the research are summarized as follows: The design characteristic of the facade of the main adminstration building in university has chronologically changed. First of all, in the 1940's, symmetry emphasized on the center of building, superimposition, division, pediment, and arch were marked. Then, superimposition was prominent in the 1950's and symmetry emphasized on the center of building was shown in the 1960s again. Flat roof was in the 1970's, 1990s and 2000's. Finally, pediment was dominant in the 1980's. The design elements of the main administration building can be samples of chronological styles of architecture. Facade design, with proper design of the past and recent times, includes the meaning that achieve the great purpose of the university by emphasizing visual images.

• Korean Institute of Interior Design Journal
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• no.22
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• pp.102-109
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• 2000

The purpose of this study is to understand various styles of Korean house living, up to the present, to identify apartment living as the main house living, and plan and propose the interior unit spaces for apartment house based on the analysis on living space. A survey study was conducted to deduce the traditional major life style and its changes along with favorable housing spaces. In conclusion, this study proposed the unit space planning requirements that satisfies the conceptual and interior elements for habitant's characteristics and preference according to major life style as follow; 1) As the Ahn-bang(master bed room) has been changed from traditional space concept, it is mainly used as private space for husband and wife, and its utilized period is mostly at night time, the back-arrangement of the Ahn-bang should be considered. 2) As the living room is central space in the apartment housing and has complex functions which is utilized as space for family gathering and guest reception similar to the Ahn-bang of the traditional house, it should secure more space and it is desirable to arrange the space as open type by combining the pathway area. 3) As for the kitchen/dining room, the kitchen should be isolated from external attraction and the space for storing and preparing traditional foods should also considered, and the dining room should be arranged as open type. This study also suggests that since the apartment housing must be an integrated environment for habitants which satisfy behavioral, physical and mental elements simultaneously, the unit housing space should be constantly analyzed in various ways to produce a housing space which meet both their changing major life style and the temporal environment.

• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.233-242
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• 2012

The purpose of this study is to analyze the pattern of tenant layout for selected cases of five different Urban Entertainment Center(UEC) in Seoul. This research deals with the process of gaining tenant layout pattern of 40 different types. It is composed of three combination unit with tenants of the same or different consumption mode, which is divided into four different functions of retail, entertainment, dining, and service. Then, every tenant of research cases is classified as one of the fabric type, and the data is analyzed to gain its frequency rate with SPSS 14.0 program. The following is the overall explanation of the result for this research. The frequency of tenant layout pattern between the same consumption mode shows the high rate when compared to the other patterns with different consumption mode. For example, the frequency rate of tenant layout pattern which retail and dining consumption mode are placed side by side like RRR and DDD is high. Interestingly, the frequency rate of RRR type of tenant layout pattern that sells the similar products shows especially high level. It can provide the effective environment for shoppers to compare retail goods in many different stores as producing synergic effects when they are located near each other, so this strategy should be considered when planning tenants in UEC environment. Moreover, in case of dining tenants, when they are clustered together in the UEC environment it can play a role as an anchor tenant. Tenant layout pattern of dining-retail and dining-service consumption mode shows the high frequency rate than other layout pattern with other consumption mode. Besides, entertainment consumption tenants combined with dining or retail tenants show the high frequency rate when compared to the pattern combined with service consumption mode.